JEE Main & Advanced Chemistry Thermodynamics / रासायनिक उष्मागतिकी Question Bank

done Heat of reaction Total Questions - 172

• question_answer1)
  If \[C+{{O}_{2}}\to C{{O}_{2}}+94.2\,kcal\]                 \[{{H}_{2}}+\frac{1}{2}{{O}_{2}}\to {{H}_{2}}O+68.3\,kcal\]                 \[C{{H}_{4}}+2{{O}_{2}}\to C{{O}_{2}}+2{{H}_{2}}O+210.8\,kcal\]                 then the possible heat of methane will be           [MP PET 1990]
  A)
                  47.3 kcal               done clear
  B)
                  20.0 kcal done clear
  C)
                  45.9 kcal               done clear
  D)
                  ? 47.3 kcal done clear
  View Solution play_arrow

• question_answer2)
  Molar heat of vaporisation of a liquid is \[6kJ\,mo{{l}^{-1}}\]. If the entropy change is \[16J\,mo{{l}^{-1}}\,{{K}^{-1}}\], the boiling point of the liquid is [KCET 2005]
  A)
                  \[{{375}^{o}}C\]                done clear
  B)
                  \[375K\] done clear
  C)
                  \[273K\]               done clear
  D)
                  \[{{102}^{o}}C\] done clear
  View Solution play_arrow

• question_answer3)
  The enthalpy of fusion of ice per mole
  A)
                  18 kJ      done clear
  B)
                  8 kJ done clear
  C)
                  80 kJ      done clear
  D)
                  6 kJ done clear
  View Solution play_arrow

• question_answer4)
  In which of the following neutralisation reactions, the heat  of neutralisation will be highest [MP PMT 1989, 91; AIIMS 1999]
  A)
                  \[N{{H}_{4}}OH\] and \[C{{H}_{3}}COOH\] done clear
  B)
                  \[N{{H}_{4}}OH\]  and \[HCl\] done clear
  C)
                  \[NaOH\] and \[C{{H}_{3}}COOH\] done clear
  D)
                  \[NaOH\] and \[HCl\] done clear
  View Solution play_arrow

• question_answer5)
  If  \[S+{{O}_{2}}\to S{{O}_{2}};\,(\Delta H=-298.2)\]                 \[S{{O}_{2}}+\frac{1}{2}{{O}_{2}}\to S{{O}_{3}};\,(\Delta H=-98.2)\]                 \[S{{O}_{3}}+{{H}_{2}}O\to {{H}_{2}}S{{O}_{4}};\,(\Delta H=-130.2)\]                 \[{{H}_{2}}+\frac{1}{2}{{O}_{2}}\to {{H}_{2}}O;\,(\Delta H=-287.3)\]                 then the enthalpy of formation of \[{{H}_{2}}S{{O}_{4}}\] at 298K will be [DPMT 1983; Orissa JEE 2005]
  A)
                  \[-433.7\,kJ\]     done clear
  B)
                  \[-650.3\,kJ\] done clear
  C)
                  \[+320.5\,kJ\]    done clear
  D)
                  \[-813.9\,kJ\] done clear
  View Solution play_arrow

• question_answer6)
  From Kirchhoff's equation which factor affects the heat of reaction         [MP PMT 1990]
  A)
                  Pressure              done clear
  B)
                  Temperature done clear
  C)
                  Volume done clear
  D)
                  Molecularity done clear
  View Solution play_arrow

• question_answer7)
  The molar neutralization heat for \[KOH\] and \[HN{{O}_{3}}\] as compared to molar neutralization heat of \[NaOH\]  and \[HCl\] [MP PMT 1989]
  A)
                  Less       done clear
  B)
                  More done clear
  C)
                  Equal     done clear
  D)
                  Depends on pressure done clear
  View Solution play_arrow

• question_answer8)
  An exothermic reaction is one in which the reacting substances [CPMT 1974, 79; Bihar MEE 1982;  KCET 1992; JIPMER 2001]
  A)
                  Have more energy than the products done clear
  B)
                  Have less energy than the products done clear
  C)
                  Are at a higher temperature than the product done clear
  D)
                  None of the above done clear
  View Solution play_arrow

• question_answer9)
  The heat evolved in the combustion of benzene is given by                 \[{{C}_{6}}{{H}_{6}}+7\frac{1}{2}{{O}_{2}}\to 6C{{O}_{2}}(g)+3{{H}_{2}}O(l);\,\Delta H=-3264.6\,kJ\]                 Which of the following quantities of heat energy will be evolved when \[39\,g\,{{C}_{6}}{{H}_{6}}\] are burnt [NCERT 1978; MP PET 1990; JIPMER 2001]
  A)
                  816.15 kJ              done clear
  B)
                  1632.3 kJ done clear
  C)
                  6528.2 kJ              done clear
  D)
                  2448.45 kJ done clear
  View Solution play_arrow

• question_answer10)
  Thermochemical reactions                  \[C(\text{graphite})+\frac{1}{2}{{O}_{2}}(g)\to CO(g);\,\Delta H=-110.5\,kJ\]                 \[CO(g)+\frac{1}{2}{{O}_{2}}(g)\to C{{O}_{2}}(g);\,\Delta H=-283.2\,kJ\]                 From the above reaction, the heat of reaction for \[C(\text{graphite})+{{O}_{2}}(g)\to C{{O}_{2}}(g)\] will be [CPMT 1988; MP PMT 1989]
  A)
                  ?  393.7 kJ            done clear
  B)
                  + 393.7 kJ done clear
  C)
                  ? 172.7 kJ             done clear
  D)
                  + 172.7 kJ done clear
  View Solution play_arrow

• question_answer11)
  The following is (are) endothermic reaction         [IIT  JEE 1999]
  A)
                  Combustion of methane done clear
  B)
                  Decomposition of water done clear
  C)
                  Dehydrogenation of ethane to ethylene done clear
  D)
                  Conversion of graphite to diamond done clear
  View Solution play_arrow

• question_answer12)
  Evaporation of water is [CPMT 1973; DPMT 1982; MP PMT 1989; MP PET 1999]
  A)
                  An endothermic change done clear
  B)
                  An exothermic change done clear
  C)
                  A process where no heat change occurs done clear
  D)
                  A process accompanied by chemical reaction done clear
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• question_answer13)
  An exothermic reaction is one which [NCERT 1977; MP PMT 1990]
  A)
                  Takes place only on heating done clear
  B)
                  Is accompanied by a flame done clear
  C)
                  Is accompanied by a absorption of heat done clear
  D)
                  Is accompanied by evolution of heat done clear
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• question_answer14)
  An endothermic reaction is one in which [MNR 1980; NCERT 1976]
  A)
                  Heat is converted into electricity done clear
  B)
                  Heat is absorbed done clear
  C)
                  Heat is evolved done clear
  D)
                  Heat is converted into mechanical work done clear
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• question_answer15)
  Which of the following statement is correct [NCERT 1978]
  A)
                  \[\Delta H\] is positive for exothermic reaction done clear
  B)
                  \[\Delta H\] is negative for endothermic reaction done clear
  C)
                  The heat of neutralization of strong acid and strong base is always the same done clear
  D)
                  The enthalpy of fusion is negative done clear
  View Solution play_arrow

• question_answer16)
  The absolute enthalphy of neutralisation of the reaction \[MgO(s)+2HCl(aq)\to MgC{{l}_{2}}(aq)+{{H}_{2}}O(l)\]will be [CBSE PMT 2005]
  A)
                  Less than \[-57.33\ kJ\ mo{{l}^{-1}}\] done clear
  B)
                  \[-57.33\ kJ\ mo{{l}^{-1}}\] done clear
  C)
                  Greater than \[-57.33\ kJ\ mo{{l}^{-1}}\] done clear
  D)
                  \[57.33\ kJ\ mo{{l}^{-1}}\] done clear
  View Solution play_arrow

• question_answer17)
  \[\Delta H{{{}^\circ }_{f}}\] (298K) of methanol is given by the chemical equation             [AIIMS 2005]
  A)
                  \[C{{H}_{4}}(g)+1/2{{O}_{2}}(g)\to C{{H}_{3}}OH(g)\] done clear
  B)
                  C (graphite) \[+1/2{{O}_{2}}(g)+2{{H}_{2}}(g)\to C{{H}_{3}}OH(l)\] done clear
  C)
                  C (diamond) \[+1/2{{O}_{2}}(g)+2{{H}_{2}}(g)\to C{{H}_{3}}OH(l)\] done clear
  D)
                  \[CO(g)+2{{H}_{2}}(g)\to C{{H}_{3}}OH(l)\] done clear
  View Solution play_arrow

• question_answer18)
  If \[\Delta H_{f}^{o}\] for \[{{H}_{2}}{{O}_{2}}\] and \[{{H}_{2}}O\] are \[-188\,kJ/mole\] and \[-286\,kJ/mole\]. What will be the enthalpy change of the reaction \[2{{H}_{2}}{{O}_{2}}(l)\to 2{{H}_{2}}O(l)+{{O}_{2}}(g)\]        [MP PMT 1992]
  A)
                  \[-196\,kJ/mole\]            done clear
  B)
                  \[146\,kJ/mole\] done clear
  C)
                  \[-494\,kJ/mole\]            done clear
  D)
                  \[-98\,kJ/mole\] done clear
  View Solution play_arrow

• question_answer19)
  The heat of transition \[(\Delta {{H}_{t}})\] of graphite into diamond would be, where                 \[C(\text{graphite})+{{O}_{2}}(g)\to C{{O}_{2}}(g);\,\,\Delta H=x\,kJ\]                 \[C(\text{diamond})\,+{{C}_{2}}(g)\to C{{O}_{2}}(g);\,\,\Delta H=y\,kJ\]               [Pb. PET 1985]
  A)
                  \[(x+y)\,kJ\,mo{{l}^{-1}}\]           done clear
  B)
                  \[(x-y)\,kJ\,mo{{l}^{-1}}\] done clear
  C)
                  \[(y-x)\,kJ\,mo{{l}^{-1}}\]            done clear
  D)
                  None of these done clear
  View Solution play_arrow

• question_answer20)
  Correct relationship between heat of fusion \[(\Delta {{H}_{fus}})\], heat of vaporization \[(\Delta {{H}_{vap}})\] and heat of sublimation \[(\Delta {{H}_{sub}})\] is
  A)
                  \[\Delta {{H}_{fus}}=\Delta {{H}_{vap}}+\Delta {{H}_{sub}}\] done clear
  B)
                  \[\Delta {{H}_{vap}}=\Delta {{H}_{fus}}+\Delta {{H}_{sub}}\] done clear
  C)
                  \[\Delta {{H}_{sub}}=\Delta {{H}_{vap}}+\Delta {{H}_{fus}}\] done clear
  D)
                  \[\Delta {{H}_{sub}}=\Delta {{H}_{vap}}-\Delta {{H}_{fus}}\] done clear
  View Solution play_arrow

• question_answer21)
  Which of the following is an example of endothermic reaction   [MP PMT 1980]
  A)
                  \[{{C}_{2}}{{H}_{2}}+2{{H}_{2}}\to {{C}_{2}}{{H}_{6}};\,\,\Delta E=-314.0\,kJ\] done clear
  B)
                  \[C+{{O}_{2}}\to C{{O}_{2}};\,\,\Delta E=-393.5\,kJ\] done clear
  C)
                  \[{{N}_{2}}+{{O}_{2}}\to 2NO;\,\,\Delta E-180.5\,kJ\] done clear
  D)
                  \[2{{H}_{2}}+{{O}_{2}}\to 2{{H}_{2}}O;\,\,\Delta E+571.8\,kJ\] done clear
  View Solution play_arrow

• question_answer22)
  If the enthalpy of B is greater than of A, the reaction \[A\to B\] is             [MP PMT 1997]
  A)
                  Endothermic      done clear
  B)
                  Exothermic done clear
  C)
                  Instantaneous   done clear
  D)
                  Spontaneous done clear
  View Solution play_arrow

• question_answer23)
  Given that                 \[2C(s)+2{{O}_{2}}(g)\to 2C{{O}_{2}}(g);\,\,\Delta H=-787\,kJ\]                 \[{{H}_{2}}(g)+\frac{1}{2}{{O}_{2}}(g)\to {{H}_{2}}O(l);\,\,\Delta H=-286\,kJ\]                 \[{{C}_{2}}{{H}_{2}}(g)+2\frac{1}{2}{{O}_{2}}(g)\to 2C{{O}_{2}}(g)+{{H}_{2}}O(l);\,\Delta H=-1301\,kJ\]                 Heat of formation of acetylene is [KCET 1989; Orissa JEE 2005]
  A)
                  \[-\,1802\,kJ\]   done clear
  B)
                  \[+\,1802\,kJ\] done clear
  C)
                  \[-800\,kJ\]         done clear
  D)
                  \[+228\,kJ\] done clear
  View Solution play_arrow

• question_answer24)
  Enthalpy change for reaction,    \[\frac{1}{2}{{H}_{2}}+\frac{1}{2}C{{l}_{2}}\to HCl\], is called
  A)
                  Enthalpy of combination               done clear
  B)
                  Enthalpy of reaction done clear
  C)
                  Enthalpy of formation    done clear
  D)
                  Enthalpy of fusion done clear
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• question_answer25)
  The enthalpy of neutralization is about 57.3 kJ for the pair
  A)
                  \[HCl\] and \[N{{H}_{4}}OH\] done clear
  B)
                  \[N{{H}_{4}}OH\] and \[HN{{O}_{3}}\] done clear
  C)
                  \[HCl\] and \[NaOH\] done clear
  D)
                  \[C{{H}_{3}}COOH\] and \[NaOH\] done clear
  View Solution play_arrow

• question_answer26)
  Conversion of oxygen to ozone represented by the equation \[3{{O}_{2}}\to 2{{O}_{3}}\] is an endothermic reaction. Enthalpy change \[\Delta H\] accompanying the reaction              [KCET 1988, 92]
  A)
                  Is negative          done clear
  B)
                  Is positive done clear
  C)
                  Is zero   done clear
  D)
                  Depends on temperature done clear
  View Solution play_arrow

• question_answer27)
  The mutual heat of neutralisation of 40 gm of \[NaOH\] and 60 gm \[C{{H}_{3}}COOH\] will be   [MP PET/PMT 1988]
  A)
                  56.1 kcal               done clear
  B)
                  Less than 56.1 kcal done clear
  C)
                  More than 56.1 kcal        done clear
  D)
                  13.7 kcal done clear
  View Solution play_arrow

• question_answer28)
  The heat of formations of \[CO(g)\] and \[C{{O}_{2}}(g)\] are \[-26.4\] kcal and \[-94.0\] kcal respectively. The heat of combustion of carbon monoxide will be [MP PET/PMT 1988; EAMCET 1993]
  A)
                  \[+26.4\,kcal\]   done clear
  B)
                  \[-67.6\,kcal\] done clear
  C)
                  \[-120.6\,kcal\] done clear
  D)
                  \[+52.8\,kcal\] done clear
  View Solution play_arrow

• question_answer29)
  The enthalpy of combustion at 25°C of H2, cyclohexane (C6H12) and cyclohexene (C6H10) are ?241, ?3920 and ?800 KJ / mole respectively. The heat of hydrogenation of cyclohexene is                [BHU 2005]
  A)
                  ? 121 KJ / mole  done clear
  B)
                  + 121 KJ / mole done clear
  C)
                  ? 242 KJ / mole  done clear
  D)
                  + 242 KJ / mole done clear
  View Solution play_arrow

• question_answer30)
  Heat of neutralisation of \[N{{H}_{4}}OH\] and \[HCl\] is [EAMCET 1980; Roorkee 1990; MP PMT 1994]
  A)
                  \[13.7\,kcal\]     done clear
  B)
                  \[>\,13.7\,kcal\] done clear
  C)
                  \[<\,13.7\,kcal\]               done clear
  D)
                  None of the above done clear
  View Solution play_arrow

• question_answer31)
  Heat of combustion \[\Delta H\] of \[C{{H}_{4}},\,{{C}_{2}}{{H}_{6}},\,{{C}_{2}}{{H}_{4}}\] and \[{{C}_{2}}{{H}_{2}}\] gases are ? 212.8, ? 373.0, ? 337.0 and ? 310.5 kcal respectively at the same temperature. The best fuel among these gases is
  A)
                  \[C{{H}_{4}}\]    done clear
  B)
                  \[{{C}_{2}}{{H}_{6}}\] done clear
  C)
                  \[{{C}_{2}}{{H}_{4}}\]     done clear
  D)
                  \[{{C}_{2}}{{H}_{2}}\] done clear
  View Solution play_arrow

• question_answer32)
  Heat of formation of \[C{{O}_{2}}(g),\,\,{{H}_{2}}O(l)\] and \[C{{H}_{4}}(g)\] are        ? 94.0, ? 68.4 and ? 17.9 kcal respectively. The heat of combustion of methane is
  A)
                  ? 212.9 kcal         done clear
  B)
                  ? 136.8 kcal done clear
  C)
                  ? 304.3 kcal done clear
  D)
                  ? 105.2 kcal done clear
  View Solution play_arrow

• question_answer33)
  The heat of reaction does not depend upon
  A)
                  Temperature of the reaction done clear
  B)
                  Physical state of reactants and products done clear
  C)
                  Whether the reaction is carried out at constant pressure or at constant volume done clear
  D)
                  The method by which the final products are obtained from the reactants done clear
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• question_answer34)
  Heat of neutralisation of a strong acid by a strong base is a constant value because          [KCET 1984]
  A)
                  Salt formed does not hydrolyse done clear
  B)
                  Only \[{{H}^{+}}\] and \[O{{H}^{-}}\] ions react in every case done clear
  C)
                  The strong base and strong acid react completely done clear
  D)
                  The strong base and strong acid react in aqueous solution done clear
  View Solution play_arrow

• question_answer35)
  Heat of neutralisation of an acid by a base is highest when [KCET 1985]
  A)
                  Both the acid and base are weak done clear
  B)
                  Both the acid and base are strong done clear
  C)
                  The acid is strong and the base is weak done clear
  D)
                  The acid is weak and the base is strong done clear
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• question_answer36)
  The standard molar heat of formation of ethane, \[C{{O}_{2}}\] and water (l) are respectively ? 21.1, ? 94.1 and ? 68.3 kcal. The standard molar heat of combustion of ethane will be [IIT JEE 1986; DPMT 2005]
  A)
                  ? 372 kcal            done clear
  B)
                  162 kcal done clear
  C)
                  ?240 kcal             done clear
  D)
                  183.5 kcal done clear
  View Solution play_arrow

• question_answer37)
  Which of the following reaction is endothermic [AFMC 1988]
  A)
                  \[CaC{{O}_{3}}\to CaO+C{{O}_{2}}\] done clear
  B)
                  \[Fe+S\to FeS\] done clear
  C)
                  \[NaOH+HCl\to NaCl+{{H}_{2}}O\] done clear
  D)
                  \[C{{H}_{4}}+2{{O}_{2}}\to C{{O}_{2}}+2{{H}_{2}}O\] done clear
  View Solution play_arrow

• question_answer38)
  In the reaction                 \[C{{O}_{2}}(g)+{{H}_{2}}(g)\to CO(g)+{{H}_{2}}O(g);\,\Delta H=80\,kJ\]                 \[\Delta H\] is known as [CPMT 1987; KCET 1993; Bihar CEE 1995]
  A)
                  Heat of formation            done clear
  B)
                  Heat of combustion done clear
  C)
                  Heat of neutralization    done clear
  D)
                  Heat of reaction done clear
  View Solution play_arrow

• question_answer39)
  Heat of combustion of a substance [CPMT 1987, 96; AFMC 1992]
  A)
                  Is always positive done clear
  B)
                  Is always negative done clear
  C)
                  Is equal to heat of formation done clear
  D)
                  Nothing can be said without reaction done clear
  View Solution play_arrow

• question_answer40)
  The heat change for the reaction \[{{H}_{2}}+\frac{1}{2}{{O}_{2}}\to {{H}_{2}}O\] is called
  A)
                  Heat of reaction               done clear
  B)
                  Heat of formation done clear
  C)
                  Heat of vaporisation       done clear
  D)
                  None of the above done clear
  View Solution play_arrow

• question_answer41)
  The heat change \[\Delta H\] for the reaction                 \[2CO+{{O}_{2}}\to 2C{{O}_{2}};\,\Delta H=-135\,kcal\] is called
  A)
                  Heat of formation            done clear
  B)
                  Heat of reaction done clear
  C)
                  Heat of combustion        done clear
  D)
                  Heat of solution done clear
  View Solution play_arrow

• question_answer42)
  The heats of combustion of rhombic and monoclinic sulphur are respectively 70960 and 71030 calories. What will be the heat of conversion of rhombic sulphur to monoclinic [MP PMT/PET 1988]
  A)
                  70960 calories    done clear
  B)
                  71030 calories done clear
  C)
                  ? 70 calories       done clear
  D)
                  + 70 calories done clear
  View Solution play_arrow

• question_answer43)
  The heat of formation of \[{{H}_{2}}O(l)\] is ? 68.0 kcal, the  heat of formation of \[{{H}_{2}}O(g)\] is likely to be
  A)
                  ? 68.0 kcal           done clear
  B)
                  ? 67.4 kcal done clear
  C)
                  80.0 kcal               done clear
  D)
                  ? 58.3 kcal done clear
  View Solution play_arrow

• question_answer44)
  Which of the following fuels will have the highest calorific value (kJ/kg) [MP PMT 1990]
  A)
                  Charcoal               done clear
  B)
                  Kerosene done clear
  C)
                  Wood    done clear
  D)
                  Dung done clear
  View Solution play_arrow

• question_answer45)
  The heat of combustion of carbon is ?94 kcal at 1 atm pressure. The intrinsic energy of \[C{{O}_{2}}\] is
  A)
                  \[+94\,kcal\]      done clear
  B)
                  \[-\,94\,kcal\] done clear
  C)
                  \[+47\,kcal\]      done clear
  D)
                  \[-47\,kcal\] done clear
  View Solution play_arrow

• question_answer46)
  The heat of neutralisation of a strong acid and a strong alkali is \[57.0\,kJ\,mo{{l}^{-1}}\]. The heat released when \[0.5\,mole\] of \[HN{{O}_{3}}\] solution is mixed with \[0.2\,mole\] of \[KOH\] is [KCET 1991; AIIMS 2002; AMU (Engg.) 2002]
  A)
                  \[57.0\,kJ\]         done clear
  B)
                  \[11.4\,kJ\] done clear
  C)
                  \[28.5\,kJ\]         done clear
  D)
                  \[34.9\,kJ\] done clear
  View Solution play_arrow

• question_answer47)
  A solution of \[500ml\] of \[0.2\,M\,KOH\] and \[500\,ml\] of \[0.2\,M\,HCl\] is mixed and stirred; the rise in temperature is \[{{T}_{1}}\]. The experiment is repeated using \[250\,ml\] each of solution, the temperature raised is \[{{T}_{2}}\]. Which of the following is true      [EAMCET 1987; MP PET 1994]
  A)
                  \[{{T}_{1}}={{T}_{2}}\]   done clear
  B)
                  \[{{T}_{1}}=2{{T}_{2}}\] done clear
  C)
                  \[{{T}_{1}}=4{{T}_{2}}\] done clear
  D)
                  \[{{T}_{2}}=9{{T}_{1}}\] done clear
  View Solution play_arrow

• question_answer48)
  Enthalpy of a compound is equal to its [CMC Vellore 1991]
  A)
                  Heat of combustion        done clear
  B)
                  Heat of formation done clear
  C)
                  Heat of reaction               done clear
  D)
                  Heat of solution done clear
  E)
                  Heat of dilution done clear
  View Solution play_arrow

• question_answer49)
  Which is the best definition of ?heat of neutralization? [CMC Vellore 1991]
  A)
                  The heat set free when one gram  molecule of a base is neutralized by one gram  molecule of an acid in dilute solution at a stated temperature done clear
  B)
                  The heat absorbed when one gram molecule of an acid is neutralized by one gram  molecule of a base in dilute solution at a stated temperature done clear
  C)
              The heat set free or absorbed when one gram  atom of an acid is neutralized by one gram atom of a base at a stated temperature done clear
  D)
                  The heat set free or absorbed when a normal solution containing one gram equivalent of an acid is neutralized by a normal solution containing one gram equivalent of a base at a stated temperature done clear
  E)
                  The heat set free when one gram equivalent of an acid is neutralized by one gram equivalent of a base in dilute solution at a stated temperature done clear
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• question_answer50)
  The compound with negative heat of formation are known as    [DPMT 1981]
  A)
                  Endothermic compound done clear
  B)
                  Exothermic compound done clear
  C)
                  Heat of formation compound done clear
  D)
                  None of the above done clear
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• question_answer51)
  If \[{{H}^{+}}+O{{H}^{-}}\to {{H}_{2}}O+13.7\,kcal\], then the heat of neutralization for complete neutralization of one mole of \[{{H}_{2}}S{{O}_{4}}\] by base will be   [MP PMT 1990]
  A)
                  13.7 kcal               done clear
  B)
                  27.4 kcal done clear
  C)
                  6.85 kcal               done clear
  D)
                  3.425 kcal done clear
  View Solution play_arrow

• question_answer52)
  The lowest value of heat of neutralization is obtained for [KCET 1988; MP PMT 1990]
  A)
                  \[HCl+NaOH\] done clear
  B)
                  \[C{{H}_{3}}COOH+N{{H}_{4}}OH\] done clear
  C)
                  \[N{{H}_{4}}OH+HCl\] done clear
  D)
                  \[NaOH+C{{H}_{3}}COOH\] done clear
  View Solution play_arrow

• question_answer53)
  Heat of neutralisation for the given reaction \[NaOH+HCl\to NaCl+{{H}_{2}}O\] is \[57.1\,kJ\,mo{{l}^{-1}}\]. What will be the heat released when \[0.25\,mole\] of \[NaOH\] is titrated against \[0.25\,mole\] of \[HCl\]           [CPMT 1990]
  A)
                  \[22.5\,kJ\,mo{{l}^{-1}}\]             done clear
  B)
                  \[57.1\,kJ\,mo{{l}^{-1}}\] done clear
  C)
                  \[14.3\,kJ\,mo{{l}^{-1}}\]             done clear
  D)
                  \[28.6\,kJ\,mo{{l}^{-1}}\] done clear
  View Solution play_arrow

• question_answer54)
  Reaction, \[{{H}_{2}}(g)+{{I}_{2}}(g)\to 2HI(g)\] \[\Delta H=-12.40\,kcal\]. According to this, the heat of formation of HI will be [MP PET 1990]
  A)
                  12.4 kcal               done clear
  B)
                  ? 12.4 kcal done clear
  C)
                  ? 6.20 kcal done clear
  D)
                  6.20 kcal done clear
  View Solution play_arrow

• question_answer55)
  All reactions with chemical dissociation are          [MP PMT 1990]
  A)
                  Reversible done clear
  B)
                  Reversible and endothermic done clear
  C)
                  Exothermic done clear
  D)
                  Reversible or irriversible and endothermic or exothermic done clear
  View Solution play_arrow

• question_answer56)
  The heat of formation is the change in enthalpy accompanying the formation of a substance from its elements at 298 K and 1 atm pressure. Since the enthalpies of elements are taken to be zero, the heat of formation \[(\Delta H)\] of compounds        [NCERT 1978; KCET 1993]
  A)
                  Is always negative done clear
  B)
                  Is always positive done clear
  C)
                  May be negative or positive done clear
  D)
                  Is zero done clear
  View Solution play_arrow

• question_answer57)
  The heat of combustion of \[C{{H}_{4(g)}},\,{{C}_{(\text{graphite})}}\] and \[{{H}_{2(g)}}\] are \[20\,kcal,\,-40\,kcal\] and \[-10\,kcal\] respectively. The heat of formation of methane is         [EAMCET 1998]
  A)
                  \[-4.0\,kcal\]      done clear
  B)
                  \[+40\,kcal\] done clear
  C)
                  \[-80\,kcal\]       done clear
  D)
                  \[+80\,kcal\] done clear
  View Solution play_arrow

• question_answer58)
  If a chemical reaction is accompanied by the evolution of heat, it is          [BHU 1979]
  A)
                  Catalytic               done clear
  B)
                  Photochemical done clear
  C)
                  Endothermic      done clear
  D)
                  Exothermic done clear
  View Solution play_arrow

• question_answer59)
  A reaction that takes place with the absorption of energy is [EAMCET 1977]
  A)
                  Burning of a candle         done clear
  B)
                  Rusting of iron done clear
  C)
                  Electrolysis of water       done clear
  D)
                  Digestion of food done clear
  View Solution play_arrow

• question_answer60)
  Which of the following is an endothermic reaction [EAMCET 1980; MP PMT 1980; IIT JEE 1989; JIPMER 2002]
  A)
                  \[2{{H}_{2}}+{{O}_{2}}\to 2{{H}_{2}}O\] done clear
  B)
                  \[{{N}_{2}}+{{O}_{2}}\to 2NO\] done clear
  C)
                  \[2NaOH+{{H}_{2}}S{{O}_{4}}\to N{{a}_{2}}S{{O}_{4}}+2{{H}_{2}}O\] done clear
  D)
                  \[3{{O}_{2}}+{{C}_{2}}{{H}_{5}}OH\to 2C{{O}_{2}}+3{{H}_{2}}O\] done clear
  View Solution play_arrow

• question_answer61)
  One of the phenomena which cannot be described as combustion is      [EAMCET 1979]
  A)
                  Oxidation of coal in air done clear
  B)
                  Burning of magnesium in nitrogen done clear
  C)
                  Reaction of antimony in chlorine done clear
  D)
                  Lighting of an electric lamp done clear
  View Solution play_arrow

• question_answer62)
  Which of the following statements is correct about heat  of combustion                [MADT Bihar 1982]
  A)
                  It may be exothermic in some cases and endothermic in other cases done clear
  B)
                  It is applicable to gaseous substances only done clear
  C)
                  It is always an exothermic reaction done clear
  D)
                  Its value does not change with temperature done clear
  View Solution play_arrow

• question_answer63)
  \[{{H}_{2}}+\frac{1}{2}{{O}_{2}}\to {{H}_{2}}O;\,\Delta H=-68.39\,kcal\]                 \[K+{{H}_{2}}O+\]Water \[\to KOH(aq)+\frac{1}{2}{{H}_{2}};\,\Delta H=-48\,kcal\]                 \[KOH+\]Water \[\to KOH(aq);\,\Delta H=-14\,kcal\]                 The heat of formation of \[KOH\] is (in kcal)        [CPMT 1988]
  A)
                  \[-68.39+48-14\]               done clear
  B)
                  \[-68.39-48+14\] done clear
  C)
                  \[68.39-48+14\]                done clear
  D)
                  68.39 + 48 + 14 done clear
  View Solution play_arrow

• question_answer64)
  Which of the following reaction can be used to define the heat of formation of \[C{{O}_{2}}(g)\] [MP PMT 1989; MH CET 2001]
  A)
                  \[C\text{(graphite)}+{{O}_{2}}(g)=C{{O}_{2}}(g)\] done clear
  B)
                  \[C{{H}_{4}}(g)+2{{O}_{2}}(g)=C{{O}_{2}}(g)+2{{H}_{2}}O(l)\] done clear
  C)
                  \[CO(g)+\frac{1}{2}{{O}_{2}}(g)=C{{O}_{2}}(g)\] done clear
  D)
                  \[{{C}_{6}}{{H}_{6}}(l)+7\frac{1}{2}{{O}_{2}}(g)=6C{{O}_{2}}+3{{H}_{2}}O(l)\] done clear
  View Solution play_arrow

• question_answer65)
  The enthalpy of formation of ammonia is \[-46.0\,kJ\,mo{{l}^{-1}}\]. The enthalpy change for the reaction \[2N{{H}_{3}}(g)\to 2{{N}_{2}}(g)+3{{H}_{2}}(g)\] is
  A)
                  46.0 kJ \[mo{{l}^{-1}}\] done clear
  B)
                  92.0 kJ \[mo{{l}^{-1}}\] done clear
  C)
                  ? 23.0 kJ \[mo{{l}^{-1}}\]              done clear
  D)
                  ? 92.0 kJ \[mo{{l}^{-1}}\] done clear
  View Solution play_arrow

• question_answer66)
  The heat of combustion of benzene determined in a bomb calorimeter is \[-870\,kcal\,mo{{l}^{-1}}\] at \[{{25}^{o}}C\]. The value  of \[\Delta E\] for the reaction is
  A)
                  \[-1740\,kcal\]   done clear
  B)
                  \[-870\,kcal\] done clear
  C)
                  \[-872\,kcal\]     done clear
  D)
                  \[-874\,kcal\] done clear
  View Solution play_arrow

• question_answer67)
  The formation of water from \[{{H}_{2}}(g)\] and \[{{O}_{2}}(g)\] is an exothermic reaction because       [MP PMT/PET 1988]
  A)
                  The chemical energy of \[{{H}_{2}}(g)\] and \[{{O}_{2}}(g)\] is more than that of water done clear
  B)
                  The chemical energy of \[{{H}_{2}}(g)\] and \[{{O}_{2}}(g)\] is less than that of water done clear
  C)
                  Not dependent on energy done clear
  D)
                  The temperature of \[{{H}_{2}}(g)\] and \[{{O}_{2}}(g)\] is more than that of water done clear
  View Solution play_arrow

• question_answer68)
  In the reaction for the transition of carbon in the diamond form to carbon in the graphite form, \[\Delta H\] is \[-453.5\,cal\]. This points out that                [BHU 1981; KCET 1986, 89]
  A)
                  Graphite is chemically different from diamond done clear
  B)
                  Graphite is as stable as diamond done clear
  C)
                  Graphite is more stable than diamond done clear
  D)
                  Diamond is more stable than graphite done clear
  View Solution play_arrow

• question_answer69)
  In the combustion of hydrocarbons, \[\Delta H\] is          [BHU 1981]
  A)
                  Negative              done clear
  B)
                  Zero done clear
  C)
                  Positive                done clear
  D)
                  Undeterminate done clear
  View Solution play_arrow

• question_answer70)
  The standard heats of formation in kcal \[mo{{l}^{-1}}\] of \[N{{O}_{2}}(g)\] and \[{{N}_{2}}{{O}_{4}}(g)\] are 8.0 and 2.0 respectively. The heat of dimerization of \[N{{O}_{2}}\] in \[kcal\] is                 \[2N{{O}_{2}}(g)={{N}_{2}}{{O}_{4}}(g)\]                                              [NCERT 1983]
  A)
                  10.0        done clear
  B)
                  ? 6.0 done clear
  C)
                  ? 12.0    done clear
  D)
                  ? 14.0 done clear
  View Solution play_arrow

• question_answer71)
  The difference between heats of reaction at constant pressure and at constant volume for the reaction \[2{{C}_{6}}{{H}_{6}}(l)+15{{O}_{2}}(g)\to 12C{{O}_{2}}(g)+6{{H}_{2}}O(l)\]at \[{{25}^{o}}C\]in kJ is [IIT JEE 1991; Kerala PMT 2004]
  A)
                  ?7.43     done clear
  B)
                  + 3.72 done clear
  C)
                  ?3.72     done clear
  D)
                  + 7.43 done clear
  View Solution play_arrow

• question_answer72)
  \[C\](diamond) \[+{{C}_{2}}(g)\to C{{O}_{2}}(g);\,\Delta H=-395\] kJ                 \[C\] (graphite) \[+{{O}_{2}}(g)\to C{{O}_{2}}(g);\,\Delta H=-393.5\] kJ                 From the data, the \[\Delta H\] when diamond is formed from graphite, is           [CBSE PMT 1989; BHU 1987]
  A)
                  \[-1.5\,kJ\]          done clear
  B)
                  \[+\,1.5\,kJ\] done clear
  C)
                  \[+\,3.0\,kJ\]     done clear
  D)
                  \[-3.0\,kJ\] done clear
  View Solution play_arrow

• question_answer73)
  Which of the following values of heat of formation indicates that the product is least stable         [MP PMT 1991]
  A)
                  \[-94\,kcal\]       done clear
  B)
                  \[-\,231.6\,kcal\] done clear
  C)
                  \[+21.4\,kcal\]   done clear
  D)
                  \[+\,64.8\,kcal\] done clear
  View Solution play_arrow

• question_answer74)
  Which of the following equations correctly represents the standard heat of formation \[(\Delta H_{f}^{o})\] of methane [IIT JEE (Screening) 1992]
  A)
                  \[C(diamond)\,+2{{H}_{2}}(g)=C{{H}_{4}}(g)\] done clear
  B)
                  \[C(graphite)+2{{H}_{2}}(g)=C{{H}_{4}}(l)\] done clear
  C)
                  \[C(graphite)+2{{H}_{2}}(g)=C{{H}_{4}}(g)\] done clear
  D)
                  \[C(graphite)+4H=C{{H}_{4}}(g)\] done clear
  View Solution play_arrow

• question_answer75)
  In which of the following reactions does the heat change represent the heat of formation of water [EAMCET 1991]
  A)
                  \[2{{H}_{2}}(g)+{{O}_{2}}(g)\to 2{{H}_{2}}O(l);\,\Delta H=-116\,kcal\] done clear
  B)
                  \[{{H}_{2}}(g)+\frac{1}{2}{{O}_{2}}(g)\to {{H}_{2}}O(l);\,\Delta H=-58\,kcal\] done clear
  C)
                  \[{{H}^{+}}(aq.)+O{{H}^{-}}(aq.)\to 2{{H}_{2}}O(l);\,\Delta H=-13.7\,kcal\] done clear
  D)
                  \[{{C}_{2}}{{H}_{2}}(g)+2\frac{1}{2}{{O}_{2}}(g)\to 2C{{O}_{2}}(g)+{{H}_{2}}O(l)\];                 \[\Delta H=-310\,kcal\] done clear
  View Solution play_arrow

• question_answer76)
  Values of heats of formation for \[Si{{O}_{2}}\]and \[MgO\] are \[-48.4\] and \[-34.7\,kJ\] respectively. The heat of the reaction \[2Mg+Si{{O}_{2}}\to 2MgO+Si\] is                [KCET 1990]
  A)
                  \[21.16\,kJ\]       done clear
  B)
                  \[-21.10\,kJ\] done clear
  C)
                  \[-13.62\,kJ\]     done clear
  D)
                  \[13.6\,kJ\] done clear
  View Solution play_arrow

• question_answer77)
  Based on the following thermochemical equations                 \[{{H}_{2}}O(g)+C(s)\to CO(g)+{{H}_{2}}(g);\,\Delta H=131\,kJ\]                 \[CO(g)+\frac{1}{2}{{O}_{2}}(g)\to C{{O}_{2}}(g);\Delta H=-282\,kJ\]                 \[{{H}_{2}}(g)+\frac{1}{2}{{O}_{2}}(g)\to {{H}_{2}}O(g);\,\Delta H=-242\,kJ\]                 \[C(s)+{{O}_{2}}(g)\to C{{O}_{2}}(g);\,\Delta H=X\,kJ\]                 The value of \[X\] is                                        [CBSE PMT 1992]
  A)
                  \[-393\,kJ\]         done clear
  B)
                  \[-\,655\,kJ\] done clear
  C)
                  \[+\,393\,kJ\]    done clear
  D)
                  \[+655\,kJ\] done clear
  View Solution play_arrow

• question_answer78)
  Heat of transition is the heat evolved or absorbed when a substance is converted from                 [KCET 1984]
  A)
                  Solid to liquid done clear
  B)
                  Solid to vapour done clear
  C)
                  Liquid to vapour done clear
  D)
                  One allotropic form to another allotropic form done clear
  View Solution play_arrow

• question_answer79)
  For the allotropic change represented by equation \[C(diamond)\to C(graphite)\]; the enthalpy change is \[\Delta H=-1.89\,kJ\]. If \[6\,g\] of diamond and \[6\,g\] of graphite are separately burnt to yield carbon dioxide, the heat liberated in the first case is             [KCET 1988; DPMT 2000]
  A)
                  Less than in the second case by \[1.89\,kJ\] done clear
  B)
                  More than in the second case by \[1.89\,kJ\] done clear
  C)
                  Less than in the second case by \[11.34\,kJ\] done clear
  D)
                  More than in the second case by \[0.945\,kJ\] done clear
  View Solution play_arrow

• question_answer80)
  For an exothermic reaction [MP PET 1994; Manipal MEE 1995]
  A)
                  \[H\] of the products is less than \[H\] of the reactants done clear
  B)
                  \[H\] of the products is more than \[H\] of the reactants done clear
  C)
                  \[H\] of the products is equal to \[H\] of the reactants done clear
  D)
                  \[\Delta H\] is always positive done clear
  View Solution play_arrow

• question_answer81)
  The energy evolved is highest for which of the following reactions           [MP PET 1994]
  A)
                  \[F+{{e}^{-}}\to {{F}^{-1}}\]        done clear
  B)
                  \[Cl+{{e}^{-}}\to C{{l}^{-}}\] done clear
  C)
                  \[S+2{{e}^{-}}\to {{S}^{2-}}\] done clear
  D)
                  \[O+2{{e}^{-}}\to {{O}^{2-}}\] done clear
  View Solution play_arrow

• question_answer82)
  In the combustion of \[2.0\,gm\] of methane \[25\,kcal\] heat is liberated, heat of combustion of methane would be [MP PMT 1994]
  A)
                  \[100\,kcal\]       done clear
  B)
                  \[200\,kcal\] done clear
  C)
                  \[300\,kcal\]       done clear
  D)
                  \[400\,kcal\] done clear
  View Solution play_arrow

• question_answer83)
  Complete combustion of \[C{{H}_{4}}\] gives     [BHU 1995]
  A)
                  \[C{{O}_{2}}+{{H}_{2}}O\]            done clear
  B)
                  \[C{{O}_{2}}+{{H}_{2}}\] done clear
  C)
                  \[COC{{l}_{2}}\]                done clear
  D)
                  \[CO+C{{O}_{2}}+{{H}_{2}}O\] done clear
  View Solution play_arrow

• question_answer84)
  If enthalpies of formation of \[{{C}_{2}}{{H}_{4}}(g),\,C{{O}_{2}}(g)\] and \[{{H}_{2}}O(l)\] at \[{{25}^{o}}C\] and \[1\,atm\] pressure be 52, ? 394 and \[-286\,kJ\,mo{{l}^{-1}}\] respectively, the enthalpy of combustion of \[{{C}_{2}}{{H}_{4}}(g)\] will be [CBSE PMT 1995; AIIMS 1998; Pb. PMT 1999]
  A)
                  \[+1412\,kJ\,mo{{l}^{-1}}\]          done clear
  B)
                  \[-1412\,kJ\,mo{{l}^{-1}}\] done clear
  C)
                  \[+141.2\,kJ\,mo{{l}^{-1}}\]        done clear
  D)
                  \[-141.2\,kJ\,mo{{l}^{-1}}\] done clear
  View Solution play_arrow

• question_answer85)
  Carbon and carbon monoxide burn in oxygen to form carbon dioxide according to the following reactions                 \[C+{{O}_{2}}\to C{{O}_{2}};\,\Delta H=-394\,kJ\,mo{{l}^{-1}}\]                 \[2CO+{{O}_{2}}\to 2C{{O}_{2}};\,\Delta H=-569\,kJ\,mo{{l}^{-1}}\]                 The heat of formation of \[1\,mol\]of carbon monoxide is thus [MP PET 1995]
  A)
                  \[-219.0\,kJ\,mo{{l}^{-1}}\]         done clear
  B)
                  \[-109.5\,kJ\,mo{{l}^{-1}}\] done clear
  C)
                  \[-175.0\,kJ\,mo{{l}^{-1}}\]         done clear
  D)
                  \[-87.5\,kJ\,mo{{l}^{-1}}\] done clear
  View Solution play_arrow

• question_answer86)
  Heat of formation in the reaction                 \[{{H}_{2}}+C{{l}_{2}}\to 2HCl+44\,kcal\] is           [MP PMT 1995]
  A)
                  44  kcal done clear
  B)
                  44000  kcal done clear
  C)
                  22 kcal  done clear
  D)
                  11 kcal done clear
  View Solution play_arrow

• question_answer87)
  When water is added to quick lime, the reaction is [MP PMT 1995]
  A)
                  Exothermic         done clear
  B)
                  Endothermic done clear
  C)
                  Explosive             done clear
  D)
                  None of these done clear
  View Solution play_arrow

• question_answer88)
  In an exothermic reaction \[\Delta H\] is [MP PMT 1995; CPMT 1999]
  A)
                  Positive                done clear
  B)
                  Negative done clear
  C)
                  Zero       done clear
  D)
                  Both positive or negative done clear
  View Solution play_arrow

• question_answer89)
  The heat change for the following reaction \[C(s)+2S(s)\to C{{S}_{2}}(l)\] is known as     [MP PMT 1996]
  A)
                  Heat of vaporization       done clear
  B)
                  Heat of solution done clear
  C)
                  Heat of fusion   done clear
  D)
                  Heat of formation done clear
  View Solution play_arrow

• question_answer90)
  The enthalpy of combustion of benzene from the following data will be                 (i) \[6C(s)+3{{H}_{2}}(g)\to {{C}_{6}}{{H}_{6}}(l);\,\Delta H=+45.9\,kJ\]                 (ii) \[{{H}_{2}}(g)+\frac{1}{2}{{O}_{2}}(g)\to {{H}_{2}}O(l);\,\Delta H=-285.9\,kJ\]                 (iii) \[C(s)+{{O}_{2}}(g)\to C{{O}_{2}}(g);\,\Delta H=-393.5\,kJ\]
  A)
                  + 3172.8 kJ          done clear
  B)
                  ? 1549.2 kJ done clear
  C)
                  ? 3172.8 kJ          done clear
  D)
                  ? 3264.6 kJ done clear
  View Solution play_arrow

• question_answer91)
  Enthalpy of formation of \[HF\] and \[HCl\] are \[-\,161\,kJ\] and \[-\,92\,kJ\] respectively. Which of the following statements is incorrect  [KCET 2003]
  A)
                  \[HCl\] is more stable than \[HF\] done clear
  B)
                  \[HF\] and \[HCl\] are exothermic compounds done clear
  C)
                  The affinity of fluorine to hydrogen is greater than the affinity of chlorine to hydrogen done clear
  D)
                  \[HF\] is more stable than \[HCl\] done clear
  View Solution play_arrow

• question_answer92)
  The heat of reaction at constant pressure is given by [MP PMT 1997]
  A)
                  \[{{E}_{P}}-{{E}_{R}}\]    done clear
  B)
                  \[{{E}_{R}}-{{E}_{P}}\] done clear
  C)
                  \[{{H}_{P}}-{{H}_{R}}\]  done clear
  D)
                  \[{{H}_{R}}-{{H}_{P}}\] done clear
  View Solution play_arrow

• question_answer93)
  In an endothermic reaction, the value of \[\Delta H\] is [CBSE PMT 1999; AIIMS 1998; BHU 2000; MP PMT 2000]
  A)
                  Zero        done clear
  B)
                  Positive done clear
  C)
                  Negative done clear
  D)
                  Constant done clear
  View Solution play_arrow

• question_answer94)
  \[2.2016\,gm\] of acetaldehyde produced \[13.95\,kcal\] of heat on combustion in \[{{O}_{2}}\]. Calculate the heat of combustion of \[C{{H}_{3}}CHO\]             [Bihar CEE 1995]
  A)
                  279 kcal                done clear
  B)
                  972 kcal done clear
  C)
                  27.9 kcal               done clear
  D)
                  2.79 kcal done clear
  View Solution play_arrow

• question_answer95)
  \[C+\frac{1}{2}{{O}_{2}}\to CO;\,\Delta H=-42\,kJ\]                 \[CO+\frac{1}{2}{{O}_{2}}\to C{{O}_{2}};\,\Delta H=-24\,kJ\]                 The heat of formation of \[C{{O}_{2}}\] is                             [CPMT 1996]
  A)
                  ? 16 kJ   done clear
  B)
                  + 66  kJ done clear
  C)
                  + 16 kJ   done clear
  D)
                  ? 66  kJ done clear
  View Solution play_arrow

• question_answer96)
  Standard molar enthalpy of formation of \[C{{O}_{2}}\] is equal to [IIT JEE 1997; BHU 2001]
  A)
                  Zero done clear
  B)
                  The standard molar enthalpy of combustion of gaseous carbon done clear
  C)
                  The sum of standard molar enthalpies of formation of \[CO\] and \[{{O}_{2}}\] done clear
  D)
                  The standard molar enthalpy of combustion of carbon (graphite) done clear
  View Solution play_arrow

• question_answer97)
  In the complete combustion of butanol \[{{C}_{4}}{{H}_{9}}OH(l)\], if \[\Delta H\] is enthalpy of combustion and \[\Delta E\] is the heat of combustion at constant volume, then                [EAMCET 1997]
  A)
                  \[\Delta H<\Delta E\] done clear
  B)
                  \[\Delta H=\Delta E\] done clear
  C)
                  \[\Delta H>\Delta E\] done clear
  D)
                  \[\Delta H,\,\Delta E\] relation cannot be predicted done clear
  View Solution play_arrow

• question_answer98)
  \[C+{{O}_{2}}\to C{{O}_{2}};\,\Delta H=X\]                 \[CO+\frac{1}{2}{{O}_{2}}\to C{{O}_{2}};\,\Delta H=Y\]                 Then the heat of formation of \[CO\] is [BHU 1997; DPMT 2002]
  A)
                  \[X-Y\] done clear
  B)
                  \[Y-2X\] done clear
  C)
                  \[X+Y\]                 done clear
  D)
                  \[2X-Y\] done clear
  View Solution play_arrow

• question_answer99)
  The values of heat of formation of \[S{{O}_{2}}\] and \[S{{O}_{3}}\] are \[-298.2\,kJ\] and \[-98.2\,kJ\]. The heat of reaction of the following reaction will be                 \[S{{O}_{2}}+\frac{1}{2}{{O}_{2}}\to S{{O}_{3}}\]              [BHU 1997; CBSE PMT 2000]
  A)
                  \[-200\,kJ\]         done clear
  B)
                  \[-356.2\,kJ\] done clear
  C)
                  \[+200\,kJ\]        done clear
  D)
                  \[-396.2\,kJ\] done clear
  View Solution play_arrow

• question_answer100)
  Calculate the standard heat of formation of carbon disulphide \[(l)\], given that the standard heat of combustion of carbon \[(s)\], sulphur \[(s)\] and carbon disulphide \[(l)\] are \[-393.3,\,-293.72\] and \[-1108.76\,kJ\,mo{{l}^{-1}}\] respectively [Roorkee 1989; BHU 1997]
  A)
                  \[-128.02\,kJ\,mo{{l}^{-1}}\]       done clear
  B)
                  \[+12.802\,kJ\,mo{{l}^{-1}}\] done clear
  C)
                  \[+128.02\,kJ\,mo{{l}^{-1}}\]      done clear
  D)
                  \[-12.802\,kJ\,mo{{l}^{-1}}\] done clear
  View Solution play_arrow

• question_answer101)
  Fermentation is a reaction called              [RPMT 1997]
  A)
                  Endothermic      done clear
  B)
                  Exothermic done clear
  C)
                  Is temperature done clear
  D)
                  Reversible done clear
  View Solution play_arrow

• question_answer102)
  \[8\,gm\] of \[C{{H}_{4}}\] is completely burnt in air. The number of moles of water produced are           [Orissa JEE 1997]
  A)
                  0.5          done clear
  B)
                  1 done clear
  C)
                  2              done clear
  D)
                  18 done clear
  View Solution play_arrow

• question_answer103)
  For the reaction \[A(g)+2B(g)\to 2C(g)+3D(g)\], the value of \[\Delta E\] at \[{{27}^{o}}C\] is 19.0 kcal. The value of \[\Delta H\] for the reaction would be \[(R=2.0\,cal\,{{K}^{-1}}mo{{l}^{-1}})\] [Roorkee Qualifying 1998]
  A)
                  20.8 kcal               done clear
  B)
                  19.8 kcal done clear
  C)
                  18.8 kcal               done clear
  D)
                  20.2 kcal done clear
  View Solution play_arrow

• question_answer104)
  The enthalpy of solution of \[BaC{{l}_{2}}(s)\] and \[BaC{{l}_{2}}.2{{H}_{2}}O(s)\] are \[-20.6\] and \[8.8\,kJ\,mo{{l}^{-1}}\] respectively. The enthalpy change for the reaction \[BaC{{l}_{2}}(s)+2{{H}_{2}}O\to \] is [Roorkee Qualifying 1998]
  A)
                  29.4 kJ   done clear
  B)
                  ? 11.8 kJ done clear
  C)
                  ? 20.6 kJ               done clear
  D)
                  ? 29.4 kJ done clear
  View Solution play_arrow

• question_answer105)
  The enthalpy change of a reaction does not depend on [AIIMS 1997]
  A)
                  The state of reactants and products done clear
  B)
                  Nature of reactants and products done clear
  C)
                  Different intermediate reaction done clear
  D)
                  Initial and final enthalpy change of a reaction done clear
  View Solution play_arrow

• question_answer106)
  \[S+\frac{3}{2}{{O}_{2}}\to S{{O}_{3}}+2x\,kcal\]                 \[S{{O}_{2}}+\frac{1}{2}{{O}_{2}}\to S{{O}_{3}}+y\,kcal\]                 Find out the heat of formation of \[S{{O}_{2}}\] [AIIMS 1997; CBSE PMT 1999; KCET 1999]
  A)
                  \[2x-y\]                done clear
  B)
                  \[2x+y\] done clear
  C)
                  \[x+y\] done clear
  D)
                  \[2x/y\] done clear
  View Solution play_arrow

• question_answer107)
  The combustion enthalpies of carbon, hydrogen and methane are \[-395.5\,kJ\,mo{{l}^{-1}}\], \[-285.8\,kJ\,mo{{l}^{-1}}\] and \[-890.4\,kJ\,mo{{l}^{-1}}\] respectively at \[{{25}^{o}}C\]. The value of standard formation enthalpies of methane at that temperature is                [Pb. PMT 1998]
  A)
                  \[890.4\,kJ\,mo{{l}^{-1}}\]           done clear
  B)
                  \[-298.8\,kJ\,mo{{l}^{-1}}\] done clear
  C)
                  \[-74.7\,kJ\,mo{{l}^{-1}}\]            done clear
  D)
                  \[-107.7\,kJ\,mo{{l}^{-1}}\] done clear
  View Solution play_arrow

• question_answer108)
  Equal volumes of methanoic acid and sodium hydroxide are mixed. If \[x\] is the heat of formation of water, then heat evolved on neutralisation is              [BHU 1998]
  A)
                  More than \[x\]                done clear
  B)
                  Equal to \[x\] done clear
  C)
                  Twice of \[x\]    done clear
  D)
                  Less than \[x\] done clear
  View Solution play_arrow

• question_answer109)
  The neutralisation of a strong acid by a strong base liberates an amount of energy per mole of \[{{H}^{+}}\] that                [BHU 1998]
  A)
                  Depends upon which acid and base are involved done clear
  B)
                  Depends upon the temperature at which the reaction takes place done clear
  C)
                  Depends upon which catalyst is used done clear
  D)
                  Is always the same done clear
  View Solution play_arrow

• question_answer110)
  When \[0.5g\] of sulphur is burnt to \[S{{O}_{2}},\,4.6\,kJ\] of heat is liberated. What is the enthalpy of formation of sulphur dioxide [KCET 1998; AFMC 2001]
  A)
                  + 147.2 kJ             done clear
  B)
                  ? 147.2 kJ done clear
  C)
                  ? 294.4 kJ             done clear
  D)
                  + 294.4 kJ done clear
  View Solution play_arrow

• question_answer111)
  Ozone is prepared by passing silent electric discharge through oxygen. In this reaction   [AFMC 1998]
  A)
                  Energy is given out done clear
  B)
                  Energy is absorbed done clear
  C)
                  Oxygen is loaded with energy done clear
  D)
                  Oxygen is dissociated into atoms done clear
  View Solution play_arrow

• question_answer112)
  Combustion of glucose takes place according to the equation, \[{{C}_{6}}{{H}_{12}}{{O}_{6}}+6{{O}_{2}}\to 6C{{O}_{2}}+6{{H}_{2}}O\],\[\Delta H=-72\,kcal\]. How much energy will be required for the production of 1.6 g of glucose (Molecular mass of glucose = 180 g)   [AFMC 1999]
  A)
                  0.064 kcal            done clear
  B)
                  0.64 kcal done clear
  C)
                  6.4 kcal done clear
  D)
                  64 kcal done clear
  View Solution play_arrow

• question_answer113)
  Given that \[C(s)+{{O}_{2}}(g)\to C{{O}_{2}}(g),\Delta H=-394kJ\] \[2{{H}_{2}}(g)+{{O}_{2}}(g)\to 2{{H}_{2}}O(l),\,\Delta H=568kJ\] \[C{{H}_{4}}(g)+2{{O}_{2}}(g)\,\,\to \,\,C{{O}_{2}}(g)+2{{H}_{2}}O(l)\]\[\Delta H=-892\,kJ\] Heat of formation of \[C{{H}_{4}}\] is                                     [DCE 1999]
  A)
                  ? 70 kJ   done clear
  B)
                  71.8 kJ done clear
  C)
                  ? 244 kJ                done clear
  D)
                  + 782 kJ done clear
  View Solution play_arrow

• question_answer114)
  Calculate the heat of formation of \[PC{{l}_{5}}(s)\] from the following data \[2P(s)+3C{{l}_{2}}(g)\,\,\to \,\,2PC{{l}_{3}}(l);\,\Delta H=-151.8\,kcal\] \[PC{{l}_{3}}(l)+C{{l}_{2}}(g)\,\,\to \,\,PC{{l}_{5}}(s);\,\,\Delta H=-32.8\,kcal\]                 [JIPMER 1999]
  A)
                  ? 108.7 kcal         done clear
  B)
                  + 108.7 kcal done clear
  C)
                  ? 184.6 kcal done clear
  D)
                  + 184.6 kcal done clear
  View Solution play_arrow

• question_answer115)
  When \[50\,c{{m}^{3}}\] of a strong acid is added to \[50\,c{{m}^{3}}\] of an alkali, the temperature rises by \[{{5}^{o}}C\]. If  \[250\,c{{m}^{3}}\] of each liquid are mixed, the temperature rise would be [KCET 1999]
  A)
                  \[{{5}^{o}}C\]    done clear
  B)
                  \[{{10}^{o}}C\] done clear
  C)
                  \[{{25}^{o}}C\]  done clear
  D)
                  \[{{20}^{o}}C\] done clear
  View Solution play_arrow

• question_answer116)
  \[{{H}_{2}}(g)+\frac{1}{2}{{O}_{2}}(g)\,\,\to \,\,{{H}_{2}}O(l)\]; \[\Delta H\] at 298 K = ? 285.8 kJ The molar enthalpy of vaporisation of water at 1 atm and \[{{25}^{o}}C\] is 44 kJ. The standard enthalpy of formation of 1 mole of water vapour at \[{{25}^{o}}C\] is    [KCET 1999]
  A)
                  ? 241.8 kJ             done clear
  B)
                  241.8 kJ done clear
  C)
                  329.8 kJ done clear
  D)
                  ?329.8 kJ done clear
  View Solution play_arrow

• question_answer117)
  When 4 g of iron is burnt to ferric oxide at constant pressure, 29.28 kJ of heat is evolved. What is the enthalpy of formation of ferric oxide (At. Wt. of Fe = 56) [AIIMS 1999]
  A)
                  ? 81.98 kJ             done clear
  B)
                  ? 819.8 kJ done clear
  C)
                  ? 40.99 kJ             done clear
  D)
                  + 819.8 kJ done clear
  View Solution play_arrow

• question_answer118)
  When a strong acid, strong base or their salt are dissolved in water, they are completely ionised. If a strong acid is added to a strong base, \[{{H}^{+}}\] ions from the former combine with \[O{{H}^{-}}\] ions of the latter forming water. The formation of each water molecule liberates a certain quantity of energy and the reaction is exothermic. The heat liberated when one mole of water is formed by combining hydrochloric acid and sodium hydroxide is 13.7 kcal. The heat liberated when one mole of water is formed by combining sulphuric acid and sodium hydroxide is                 [AMU (Engg.) 1999]
  A)
                  25.5 kcal               done clear
  B)
                  8.5 kcal done clear
  C)
                  13.7 kcal               done clear
  D)
                  34 kcal done clear
  View Solution play_arrow

• question_answer119)
  2.1 g of Fe combines with S evolving 3.77 kJ. The heat of formation of FeS in kJ/mol is     [AMU (Engg.) 1999]
  A)
                  ? 1.79    done clear
  B)
                  ? 100.5 done clear
  C)
                  ? 3.77    done clear
  D)
                  None of these done clear
  View Solution play_arrow

• question_answer120)
  In the reaction: \[{{H}_{2}}+C{{l}_{2}}\,\to \,2HCl,\,\Delta H=194\,kJ\]. Heat of formation of \[HCl\] is     [KCET 2000; AFMC 2000; CPMT 2000]
  A)
                  + 97 kJ   done clear
  B)
                  + 194 kJ done clear
  C)
                  ? 194 kJ done clear
  D)
                  ? 97 kJ done clear
  View Solution play_arrow

• question_answer121)
  Enthalpy of neutralisation of acetic acid by \[NaOH\] is \[-50.6\,kJ/mol.\] and the heat of neutralisation of a strong acid with a strong base is ? 55.9 kJ/mol. What is the value of \[\Delta H\] for the ionisation of \[C{{H}_{3}}COOH\]       [AIIMS 2000]
  A)
                  + 5.3 kJ/mol        done clear
  B)
                  + 6.2 kJ/mol done clear
  C)
                  + 8.2 kJ/mol        done clear
  D)
                  + 9.3 kJ/mol done clear
  View Solution play_arrow

• question_answer122)
  Heat of neutralization of the acid-base reaction is 57.32 kJ for     [JIPMER 2000]
  A)
                  \[HN{{O}_{3}}+LiOH\]    done clear
  B)
                  \[HCOOH+KOH\] done clear
  C)
                  \[HCl+N{{H}_{4}}OH\]    done clear
  D)
                  \[C{{H}_{3}}COOH+NaOH\] done clear
  View Solution play_arrow

• question_answer123)
  The heat change for the following reaction at \[{{298}^{o}}K\] and at constant pressure is \[+7.3\,kcal\] \[{{A}_{2}}B(s)\,\to \,2A(s)+1/2\,{{B}_{2}}(g)\], \[\Delta H=+7.3\,kcal\] The heat change at constant volume would be [DCE 2000]
  A)
                  7.3 kcal done clear
  B)
                  More than 7.3 done clear
  C)
                  Zero       done clear
  D)
                  None of these done clear
  View Solution play_arrow

• question_answer124)
  The heat evolved in the combustion of benzene is given by the equation \[{{C}_{6}}{{H}_{6}}(l)+7\frac{1}{2}{{O}_{2}}(g)\,\,\to \,\,3{{H}_{2}}O(l)+6C{{O}_{2}}(g)\] \[\Delta H=781.0\,kcal\,\,mo{{l}^{-1}}\] Which of the following quantities of heat energy will be evolved when 39 g of benzene is burnt in an open container                [MP PET 2000]
  A)
                  122.25 kcal \[mo{{l}^{-1}}\]         done clear
  B)
                  390.5 kcal \[mo{{l}^{-1}}\] done clear
  C)
                  1562.0 kcal \[mo{{l}^{-1}}\]         done clear
  D)
                  586.75 kcal \[mo{{l}^{-1}}\] done clear
  View Solution play_arrow

• question_answer125)
  \[{{H}_{2}}(g)+C{{l}_{2}}(g)\,\,\to \,\,2HCl(g)\,.\,\Delta H=-44kcal\] \[2Na(s)+2HCl(g)\,\,\to \,\,2NaCl(s)+{{H}_{2}}(g),\]\[\Delta H=-152\,kcal\] For the reaction \[Na(s)+\frac{1}{2}C{{l}_{2}}(g)\,\,\to \,\,NaCl(s),\,\Delta H=\] [KCET 2000]
  A)
                  ? 108 kcal            done clear
  B)
                  ? 196 kcal done clear
  C)
                  ? 98 kcal               done clear
  D)
                  54 kcal done clear
  View Solution play_arrow

• question_answer126)
  The \[\Delta H_{f}^{o}\] for \[C{{O}_{2}}(g),\,CO(g)\] and \[{{H}_{2}}O(g)\] are ? 393.5,       ?110.5 and ? 241.8kJmol?1 respectively. The standard enthalpy change  (in kJ) for the reaction \[C{{O}_{2}}(g)+{{H}_{2}}(g)\to \] \[CO(g)+{{H}_{2}}O(g)\] is           [IIT JEE (Screening) 2000]
  A)
                  524.1     done clear
  B)
                  41.2 done clear
  C)
                  ? 262.5  done clear
  D)
                  ? 41.2 done clear
  View Solution play_arrow

• question_answer127)
  Which of the following compounds will absorb the maximum quantity of heat when dissolved in the same amount of water ? The heats of solution of these compounds at \[{{25}^{o}}C\] in kJ/mole of each solute is given in brackets                [AMU (Engg.) 2000]
  A)
                  \[HN{{O}_{3}}(\Delta H=-33)\]   done clear
  B)
                  \[KCl(\Delta H=+17.64)\] done clear
  C)
                  \[N{{H}_{4}}N{{O}_{3}}\,(\Delta H=+25.5)\]         done clear
  D)
                  \[HCl\,(\Delta H=-74.1)\] done clear
  View Solution play_arrow

• question_answer128)
  In the reaction \[C+2S\,\to \,C{{S}_{2}}+\Delta H,\,\Delta H\] is the [AMU (Engg.) 2000]
  A)
                  Heat of combustion        done clear
  B)
                  Heat of neutralization done clear
  C)
                  Heat of solution                done clear
  D)
                  None of these done clear
  View Solution play_arrow

• question_answer129)
  The heat of formation of methane \[C(s)+2{{H}_{2}}(g)\,\to \,C{{H}_{4}}(g)\] at constant pressure is 18500 cal at \[{{25}^{o}}C\]. The heat of reaction at constant volume would be           [MH CET 2000]
  A)
                  17904 cal              done clear
  B)
                  18202 cal done clear
  C)
                  18798 cal              done clear
  D)
                  19096 cal done clear
  View Solution play_arrow

• question_answer130)
  The enthalpy of combustion of \[{{C}_{6}}{{H}_{6(l)}}\] is          ? 3250 kJ. When 0.39 g of benzene is burnt excess of oxygen in an open vessel, the amount of heat evolved is [KCET 2000; AFMC 2000; DCE 2000]
  A)
                  16.25 J   done clear
  B)
                  16.25 kJ done clear
  C)
                  32.5 J     done clear
  D)
                  32.5 kJ done clear
  View Solution play_arrow

• question_answer131)
  \[C(s)+{{O}_{2}}(g)\,\to \,C{{O}_{2}};\,\,\,\,\Delta H=-94\,kcal\] \[CO(g)+\frac{1}{2}{{O}_{2}}(g)\,\to \,C{{O}_{2}};\,\,\,\Delta H=135.2\,kcal\] Then heat of formation of \[CO(g)\] is   [DCE 2001]
  A)
                  ? 26.4 kcal           done clear
  B)
                  41.2 kcal done clear
  C)
                  26.4 kcal               done clear
  D)
                  ? 229.2 kcal done clear
  View Solution play_arrow

• question_answer132)
  The heat of neutralization of \[HCl\] and \[NaOH\] is [MP PET 2001]
  A)
                  Zero       done clear
  B)
                  ? 57.3 kJ done clear
  C)
                  + 57.3 kJ               done clear
  D)
                  None of these done clear
  View Solution play_arrow

• question_answer133)
  The following thermochemical reactions are given \[M+\frac{1}{2}{{O}_{2}}\,\,\to \,\,MO+351.4\,kJ\] \[X+\frac{1}{2}{{O}_{2}}\,\,\to \,\,XO+90.8\,kJ\] It follows that the heat of reaction for the following process \[M+XO\] ⇌ \[MO+X\] is given by                 [AMU 2001]
  A)
                  422.2 kJ done clear
  B)
                  268.7 kJ done clear
  C)
                  ? 442.2 kJ             done clear
  D)
                  260.6 kJ done clear
  View Solution play_arrow

• question_answer134)
  If the heat of combustion of carbon monoxide at constant volume and at \[{{17}^{o}}C\] is ? 283.3 kJ, then its heat of combustion  at constant pressure \[(R=8.314\,J\,\text{degre}{{\text{e}}^{\text{-1}}}mo{{l}^{-1}})\]        [CPMT 2001]
  A)
                  ? 284.5 kJ             done clear
  B)
                  284.5 kJ done clear
  C)
                  384.5 kJ done clear
  D)
                  ? 384.5 kJ done clear
  View Solution play_arrow

• question_answer135)
  Heat of formation of \[{{H}_{2}}O\] is \[-188\,kJ/mole\] and \[{{H}_{2}}{{O}_{2}}\] is \[-286\,kJ/mole.\] The enthalpy change for the reaction \[2{{H}_{2}}{{O}_{2}}\,\to \,2{{H}_{2}}O+{{O}_{2}}\] is   [BHU 2001]
  A)
                  196 kJ    done clear
  B)
                  ? 196 kJ  done clear
  C)
                  984 kJ    done clear
  D)
                  ? 984 kJ done clear
  View Solution play_arrow

• question_answer136)
  The values of \[\Delta H\] for the combustion of ethene and ethyne are ? 341.1 and ? 310.0kcal respectively. Which of the following is a better fuel  [BHU 2001]
  A)
                  \[{{C}_{2}}{{H}_{2}}\]     done clear
  B)
                  \[{{C}_{2}}{{H}_{4}}\] done clear
  C)
                  Both of these    done clear
  D)
                  None of these done clear
  View Solution play_arrow

• question_answer137)
  For exothermic reaction, the equilibrium constant [JIPMER 2001]
  A)
                  Increases with increase of P done clear
  B)
                  Decreases with increase of P done clear
  C)
                  Increases with increase of temperature done clear
  D)
                  Decreases with increase of temperature done clear
  View Solution play_arrow

• question_answer138)
  In order to decompose 9 g water 142.5 kJ heat is required. Hence the enthalpy of formation of water is                [KCET 2001]
  A)
                  ? 142.5 kJ             done clear
  B)
                  + 142.5 kJ done clear
  C)
                  ? 285 kJ done clear
  D)
                  + 285 kJ done clear
  View Solution play_arrow

• question_answer139)
  What is \[\Delta n\] for combustion of 1 mole of benzene, when both the reactants and the products are gas at 298 K [Pb. PMT 2001]
  A)
                  0              done clear
  B)
                  3/2 done clear
  C)
                  ? 3/2      done clear
  D)
                  ½ done clear
  View Solution play_arrow

• question_answer140)
  If \[C+{{O}_{2}}\to C{{O}_{2}}+94.2\,kcal\] \[{{H}_{2}}+\frac{1}{2}{{O}_{2}}\to \,{{H}_{2}}O+68.3\,kcal\] \[C{{H}_{4}}+2{{O}_{2}}\,\to \,C{{O}_{2}}+2{{H}_{2}}O+210.8\,kcal\] Then the possible heat of methane will be           [UPSEAT 2001]
  A)
                  47.3 kcal               done clear
  B)
                  20.0 kcal done clear
  C)
                  45.9 kcal               done clear
  D)
                  ? 47.3 kcal done clear
  View Solution play_arrow

• question_answer141)
  Heat of neutralization of strong acid and weak base is [UPSEAT 2001]
  A)
                  \[57.1\,kJ\,mo{{l}^{-1}}\] done clear
  B)
                  \[13.7\,kJ\,mo{{l}^{-1}}\] done clear
  C)
                  Less than \[13.7\,kcal\,mo{{l}^{-1}}\] done clear
  D)
                  More than \[13.7\,kcal\,mo{{l}^{-1}}\] done clear
  View Solution play_arrow

• question_answer142)
  A system is changed from state A to state B by one path and from B to A another path. If \[{{E}_{1}}\] and \[{{E}_{2}}\] are the corresponding changes in internal energy, then [Pb. PMT 2001]
  A)
                  \[{{E}_{1}}+{{E}_{2}}=-ve\]          done clear
  B)
                  \[{{E}_{1}}+{{E}_{2}}=+ve\] done clear
  C)
                  \[{{E}_{1}}+{{E}_{2}}=0\]              done clear
  D)
                  None of these done clear
  View Solution play_arrow

• question_answer143)
  The heat evolved during the combination of 24 g C and 128 g S following the change is \[C+{{S}_{2}}\to C{{S}_{2}};\,\Delta H=22.0\,kcal\]                             [MH CET 2001]
  A)
                  11 kcal  done clear
  B)
                  32 kcal done clear
  C)
                  44 kcal  done clear
  D)
                  22 kcal done clear
  View Solution play_arrow

• question_answer144)
  When the aqueous solution of 0.5 mole \[HN{{O}_{3}}\] is mixed with the 0.3 mole of \[O{{H}^{-}}\] solution, then what will be the liberated heat (Enthalpy of neutralization is = 57.1 kJ) [Kerala CET 2005]
  A)
                  28.5 kJ done clear
  B)
                  17.1 kJ done clear
  C)
                  45.7 kJ   done clear
  D)
                  1.7 kJ done clear
  E)
                  2.85 kJ done clear
  View Solution play_arrow

• question_answer145)
  A cylinder of gas is assumed to contain 11.2 kg of butane \[({{C}_{4}}{{H}_{10}})\]. If a normal family needs 20000 kJ of energy per day. The cylinder will last: (Given that \[\Delta H\] for combustion of butane is ? 2658 kJ)       [AMU (Engg.) 2002]
  A)
                  20 days done clear
  B)
                  25 days done clear
  C)
                  26 days done clear
  D)
                  24 days done clear
  View Solution play_arrow

• question_answer146)
  Compounds with high heat of formation are less stable because               [KCET 2002]
  A)
                  High temperature is required to synthesise them done clear
  B)
                  Molecules of such compounds are distorted done clear
  C)
                  It is difficult to synthesis them done clear
  D)
                  Energy rich state leads to instability done clear
  View Solution play_arrow

• question_answer147)
  The heat evolved in the combustion of methane is given by the following equations: \[C{{H}_{4}}(g)+2{{O}_{2}}(g)\,\to \,C{{O}_{2}}(g)+{{H}_{2}}O(l);\]\[\Delta H=-890.3\,kJ\] How many grams of methane would be required to produce 445.15 kJ of heat of combustion                     [AMU 2002]
  A)
                  4 g          done clear
  B)
                  8 g done clear
  C)
                  12 g        done clear
  D)
                  16 g done clear
  View Solution play_arrow

• question_answer148)
  Heats of combustion \[(\Delta {{H}^{o}})\] for \[C(s),\,{{H}_{2}}(g)\] and \[C{{H}_{4}}(g)\] are \[-94,\,-68\] and \[-213\,kcal/mol.\] respectively. The value of \[\Delta {{H}^{o}}\] for the reaction, \[C(s)+2{{H}_{2}}(g)\,\to \,C{{H}_{4}}(g)\] is                                        [CBSE PMT 2002]
  A)
                  ? 85 kcal               done clear
  B)
                  ? 111 kcal done clear
  C)
                  ? 17 kcal               done clear
  D)
                  ? 170 kcal done clear
  View Solution play_arrow

• question_answer149)
  If the value of \[\Delta H\] in a reaction is positive, then the reaction is called      [BHU 2002]
  A)
                  Exothermic         done clear
  B)
                  Endothermic done clear
  C)
                  Polymorphic       done clear
  D)
                  Polytropic done clear
  View Solution play_arrow

• question_answer150)
  Enthalpy of neutralisation of \[N{{H}_{4}}OH\] and \[HCl\], is numerically [JIPMER 2002; Kurukshetra CEE 2002]
  A)
                  \[57.1\,\,kJ\,mo{{l}^{-1}}\]          done clear
  B)
                  \[<57.1\,\,kJ\,mo{{l}^{-1}}\] done clear
  C)
                  \[>57.1\,\,kJ\,mo{{l}^{-1}}\]       done clear
  D)
                  Zero done clear
  View Solution play_arrow

• question_answer151)
  The heat of neutralisation will be highest in         [MP PMT 2002]
  A)
                  \[N{{H}_{4}}OH\] and \[C{{H}_{3}}COOH\] done clear
  B)
                  \[N{{H}_{4}}OH\] and \[HCl\] done clear
  C)
                  \[KOH\] and \[C{{H}_{3}}COOH\] done clear
  D)
                  \[KOH\] and \[HCl\] done clear
  View Solution play_arrow

• question_answer152)
  If a mole of \[{{H}_{2}}\] molecule is heated to high temperature the following reaction takes place        [Kerala (Med.) 2002]
  A)
                  \[{{H}_{2}}(g)+436\,kJ=H(g)+H(g)\] done clear
  B)
                  \[{{H}_{2}}(g)+820\,kJ=2{{H}_{2}}(g)\] done clear
  C)
                  \[2{{H}_{2}}(g)+436\,J=2{{H}_{2}}\] done clear
  D)
                  \[{{H}_{2}}+{{H}_{2}}={{H}^{+}}+{{H}^{+}}\] done clear
  View Solution play_arrow

• question_answer153)
  Which of the following reactions is not exothermic [MP PET 2002]
  A)
                  \[C(s)+{{O}_{2}}(g)\,\to \,C{{O}_{2}}(g)\] done clear
  B)
                  \[C(s)+2S(s)\,\to \,C{{S}_{2}}(g)\] done clear
  C)
                  \[C{{H}_{4}}(g)+2{{O}_{2}}(g)\,\to \,C{{O}_{2}}(g)+2{{H}_{2}}O(l)\] done clear
  D)
                  \[CO(g)+\frac{1}{2}{{O}_{2}}(g)\,\to \,C{{O}_{2}}(g)\] done clear
  View Solution play_arrow

• question_answer154)
  On combustion, carbon forms two oxides CO and \[C{{O}_{2}}\], Heat of formation of \[C{{O}_{2}}\] gas is 94.3 kcal and that of CO is 26.0 kcal. Heat of combustion of carbon is          [JIPMER 2002]
  A)
                  26.0 kcal               done clear
  B)
                  ? 94.3 kcal done clear
  C)
                  68.3 kcal               done clear
  D)
                  ? 120.3 kcal done clear
  View Solution play_arrow

• question_answer155)
  1 mole of conc. HCl requires X moles of dilute NaOH for neutralisation and 1 mole of concentrate \[{{H}_{2}}S{{O}_{4}}\] requires Y moles of small dilute \[NaOH\] then which of the following reaction is true     [MH CET 2002]
  A)
                  \[Y=\frac{1}{2}X\]            done clear
  B)
                  \[X=\frac{1}{2}Y\] done clear
  C)
                  \[X=2Y\]               done clear
  D)
                  None of these done clear
  View Solution play_arrow

• question_answer156)
  Which of the reaction defines \[\Delta H_{f}^{o}\] [IIT -JEE (Screening) 2003]
  A)
                  \[{{C}_{(\text{diamond})}}+{{O}_{2}}(g)\,\to \,C{{O}_{2}}(g)\] done clear
  B)
                  \[\frac{1}{2}{{H}_{2}}(g)+\frac{1}{2}{{F}_{2}}(g)\,\to \,HF(g)\] done clear
  C)
                  \[{{N}_{2}}(g)+3{{H}_{2}}(g)\,\to \,2N{{H}_{3}}(g)\] done clear
  D)
                  \[CO(g)+\frac{1}{2}{{O}_{2}}(g)\,\to \,C{{O}_{2}}(g)\] done clear
  View Solution play_arrow

• question_answer157)
  One gram sample of \[N{{H}_{4}}N{{O}_{3}}\] is decomposed in a bomb calorimeter. The temperature of the calorimeter increases by 6.12 K the heat capacity of the system is 1.23 kJ/g/deg. What is the molar heat of decomposition for \[N{{H}_{4}}N{{O}_{3}}\] [AIIMS 2003]
  A)
                  ? 7.53 kJ/mol     done clear
  B)
                  ? 398.1 kJ/mol done clear
  C)
                  ? 16.1 kJ/mol     done clear
  D)
                  ? 602 kJ/mol done clear
  View Solution play_arrow

• question_answer158)
  For which one of the following equations is \[\Delta H_{\text{react}}^{o}\] equal to \[\Delta H_{f}^{o}\] for the product                [CBSE PMT  2003]
  A)
                  \[2CO(g)+{{O}_{2}}(g)\,\to \,2C{{O}_{2}}(g)\] done clear
  B)
                  \[{{N}_{2}}(g)+{{O}_{3}}(g)\,\to \,{{N}_{2}}{{O}_{3}}(g)\] done clear
  C)
                  \[C{{H}_{4}}(g)+2C{{l}_{2}}(g)\,\to \,C{{H}_{2}}C{{l}_{2}}(l)+2HCl(g)\] done clear
  D)
                  \[Xe(g)+2{{F}_{2}}(g)\,\to \,Xe{{F}_{4}}(g)\] done clear
  View Solution play_arrow

• question_answer159)
  Enthalpy change for a reaction does not depend upon [AIEEE 2003]
  A)
                  The physical states of reactants and products done clear
  B)
                  Use of different reactants for the same product done clear
  C)
                  The nature of intermediate reaction steps done clear
  D)
                  The differences in initial or final temperatures of involved substances done clear
  View Solution play_arrow

• question_answer160)
  \[{{C}_{\text{dia}}}\] + \[{{O}_{2}}\to C{{O}_{2}};\] \[\Delta H=-395.3\,kJ/mole\] \[{{C}_{gr}}+{{O}_{2}}\to C{{O}_{2}};\,\Delta H=-393.4\,kJ/mole\] \[{{C}_{gr}}\to {{C}_{\text{dia}}};\,\Delta H=\]                                   [BHU 2003]
  A)
                  ? 3.8      done clear
  B)
                  ? 1.9 done clear
  C)
                  + 3.8      done clear
  D)
                  + 1.9 done clear
  View Solution play_arrow

• question_answer161)
  What is the weight of oxygen that is required for the complete combustion of 2.8 kg of ethylene? [BVP 2003]
  A)
                  9.6 kg    done clear
  B)
                  96.0 kg done clear
  C)
                  6.4 kg    done clear
  D)
                  2.8 kg done clear
  View Solution play_arrow

• question_answer162)
  For complete neutralization of \[HCl\] with \[NaOH,\] the heat of neutralization is           [MP PET 2003]
  A)
                  \[+13.70\,kJ\,mo{{l}^{-1}}\]        done clear
  B)
                  \[-13.70\,kJ\,mo{{l}^{-1}}\] done clear
  C)
                  \[-57.32\,kJ\,mo{{l}^{-1}}\]         done clear
  D)
                  \[+57.32\,kJ\,mo{{l}^{-1}}\] done clear
  View Solution play_arrow

• question_answer163)
  The heat of combustion of carbon to \[C{{O}_{2}}\] is \[-393.5\,kJ/mol\]. The heat released upon formation of 35.2 g of \[C{{O}_{2}}\] from carbon and oxygen gas is                [UPSEAT 2004]
  A)
                  \[+\,315\,kJ\]    done clear
  B)
                  \[-\,31.5\,kJ\] done clear
  C)
                  \[-315\,kJ\]         done clear
  D)
                  \[+31.5\,kJ\] done clear
  View Solution play_arrow

• question_answer164)
  Which of the following equations correctly represents the standard heat of formation \[(\Delta H_{f}^{o})\] of methane [UPSEAT 2004]
  A)
                  \[C\](diamond) \[+4{{H}_{(g)}}\to C{{H}_{4\,(g)}}\] done clear
  B)
                  \[C\] (diamond) \[+2{{H}_{2\,(g)}}\to C{{H}_{4\,(g)}}\] done clear
  C)
                  \[C\] (graphite) \[+2{{H}_{2\,(g)}}\to C{{H}_{4\,(g)}}\] done clear
  D)
                  \[C\] (graphite) \[+4{{H}_{(g)}}\to C{{H}_{4\,(g)\,}}\] done clear
  View Solution play_arrow

• question_answer165)
  If the heat of formation of \[C{{O}_{2}}\] is\[-393\,kJ\]. The amount  of heat evolved in the formation of 0.156 kg of \[C{{O}_{2}}\] is [MH CET 2004]
  A)
                  \[-1357.9\,\,kJ\]               done clear
  B)
                  \[-1275.9\,kJ\] done clear
  C)
                  \[-1572.0\,kJ\]   done clear
  D)
                  \[-1165.5\,kJ\] done clear
  View Solution play_arrow

• question_answer166)
  Which of the following pairs has heat of neutralisation equal to 13.7 Kcals             [DCE  2003]
  A)
                  \[HCl,\,N{{H}_{4}}OH\]  done clear
  B)
                  \[HN{{O}_{3}},\,KOH\] done clear
  C)
                  \[NaOH,\,C{{H}_{3}}COOH\]       done clear
  D)
                  \[{{H}_{2}}S{{O}_{4}},\,N{{H}_{4}}OH\] done clear
  View Solution play_arrow

• question_answer167)
  The enthalpies of combustion of carbon and carbon monodie are ?393.5 and ?283 kJ mol?1 respectivley. The enthalpy of formation of carbon monoxide per mole is [AIEEE 2004]
  A)
                  \[-676.5\,kJ\]     done clear
  B)
                  \[676.5\,kJ\] done clear
  C)
                  \[110.5\,kJ\]       done clear
  D)
                  \[-110.5\,kJ\] done clear
  View Solution play_arrow

• question_answer168)
  The enthalpy of combustion of methane at \[{{25}^{o}}C\] is \[890\,kJ\]. The heat liberated when \[3.2\,g\] of methane is burnt in air is              [KCET 2004]
  A)
                  \[445\,kJ\]          done clear
  B)
                  \[278\,kJ\] done clear
  C)
                  \[-890\,kJ\]         done clear
  D)
                  \[178\,kJ\] done clear
  View Solution play_arrow

• question_answer169)
  If (i) \[C+{{O}_{2}}\to C{{O}_{2}}\], (ii) \[C+1/2{{O}_{2}}\to CO\], (iii) \[CO+1/2{{O}_{2}}\to C{{O}_{2}}\], the heats of reaction are \[Q,\,-12,\,-10\] respectively. Then \[Q=\] [Orissa JEE 2004]
  A)
                  ? 2          done clear
  B)
                  2 done clear
  C)
                  ? 22        done clear
  D)
                  ? 16 done clear
  View Solution play_arrow

• question_answer170)
  How much energy is released when 6 mole of octane is burnt in air ? Given \[\Delta H_{f}^{o}\] for \[C{{O}_{2}}(g),\,{{H}_{2}}O(g)\] and \[{{C}_{8}}{{H}_{18}}(l)\] respectively are ? 490,? 240 and + 160 kJ/mol [AIIMS 2004]
  A)
                  ? 6.2 kJ done clear
  B)
                  ? 37.4 kJ done clear
  C)
                  ? 35.5 kJ               done clear
  D)
                  ? 20.0 kJ done clear
  View Solution play_arrow

• question_answer171)
  Given : \[2Fe+\frac{3}{2}{{O}_{2}}\to F{{e}_{2}}{{O}_{3}},\,\Delta H=-193.4\,kJ\]; \[Mg+\frac{1}{2}{{O}_{2}}\to MgO,\,\Delta H=-140.2\,kJ\] What is the \[\Delta H\] of the reaction \[Mg+F{{e}_{2}}{{O}_{3}}\to 3MgO+2Fe\]           [Orissa JEE 2005]
  A)
                  ? 1802 kJ              done clear
  B)
                  +1802 kJ done clear
  C)
                  ? 800 kJ done clear
  D)
                  + 228 kJ done clear
  View Solution play_arrow

• question_answer172)
  The enthalpy change \[(\Delta H)\] for the neutralization of \[1M\,HCl\] by caustic potash in dilute solution at \[298K\] is [DPMT 2005]
  A)
                  68 kJ      done clear
  B)
                  65 kJ done clear
  C)
                  57.3 kJ   done clear
  D)
                  50 kJ done clear
  View Solution play_arrow