question_answer2) One mole of an ideal gas at 300 K is expanded isothermally from an initial volume of 1 L to 10 L. The \[\Delta E\] for this process is [AIPMT 1998]
question_answer5) If \[\Delta E\] is the heat of reaction for \[{{C}_{2}}{{H}_{5}}OH(l)+3{{O}_{2}}(g)\xrightarrow{{}}2C{{O}_{2}}(g)+3{{H}_{2}}O(l)\] at constant volume, the \[\Delta H\] (heat of reaction at constant pressure) at constant temperature is: [AIPMT 2000]
question_answer6) The entropy change in the fusion of one mole of a solid melting at \[{{27}^{o}}C\] (Latent heat of fusion,\[2930\text{ }J\text{ }mo{{l}^{-1}}\]) is: [AIPMT 2000]
question_answer8) Change in enthalpy for reaction \[2{{H}_{2}}{{O}_{2}}(l)\xrightarrow{{}}2{{H}_{2}}O(l)+{{O}_{2}}(g)\] If heat of formation of \[{{H}_{2}}{{O}_{2}}(l)\] and \[{{H}_{2}}O(l)\] are \[-188\] and \[-286\text{ }kJ/mol\] respectively: [AIPMT 2001]
question_answer9) When 1 mole gas is heated at constant volume, temperature is raised from 298 to 308K. Heat supplied to the gas is 500 J. Then which statement is correct? [AIPMT 2001]
question_answer10) Enthalpy of \[C{{H}_{4}}+\frac{1}{2}{{O}_{2}}\to C{{H}_{3}}OH\] negative. If enthalpy of combustion of \[C{{H}_{4}}\] and \[C{{H}_{3}}OH\] are \[x\] and \[y\] respectively. Then which relation is correct? [AIPMT 2001]
question_answer13) In a closed insulated container a liquid is stirred with a paddle to increase the temperature, which of the following is true? [AIPMT 2002]
question_answer14) 2 mole of ideal gas at \[27{}^\circ C\] temperature is expanded reversibly from 2 L to 20 L. Find entropy change (R = 2 cal/mol K): [AIPMT 2002]
question_answer15) Heat of combustion \[\Delta {{H}^{o}}\] for \[C(s),\,\,{{H}_{2}}(g)\] and\[C{{H}_{4}}(g)\] are -94, -68 and -213 kcal/mol. Then \[\Delta {{H}^{o}}\] for \[C(s)+2{{H}_{2}}(g)\xrightarrow[{}]{{}}C{{H}_{4}}(g)\] is: [AIPMT 2002]
question_answer16) The densities of graphite and diamond at 298 K are 2.25 and \[3.31\text{ }g\text{ }c{{m}^{-3}}\], respectively. If the standard free energy difference \[(\Delta {{G}^{o}})\] is equal to \[1895\text{ }J\text{ }mo{{l}^{-1}},\] the pressure at which graphite will be transformed into diamond at 298 K is: [AIPMT 2003]
question_answer17) On the basis of the information available from the reaction \[\frac{4}{3}Al+{{O}_{2}}\to \frac{2}{3}\,A{{l}_{2}}{{O}_{3}},\,\Delta G=-827\,kJ\,mo{{l}^{-1}}\] of \[{{O}_{2}},\] the minimum emf required to carry out an electrolysis of \[A{{I}_{2}}{{O}_{3}}\] is \[(F=96500\text{ }C\text{ }mo{{l}^{-1}})\] [AIPMT 2003]
question_answer18) The molar heat capacity of water at constant pressure, C, is \[75\text{ }J{{K}^{-1}}mo{{l}^{-1}}\]. When 1.0 kJ of heat is supplied to 100 g of water which is free to expand, the increase in temperature of water is: [AIPMT 2003]
question_answer19) What is the entropy change (in\[J{{K}^{-1}}mo{{l}^{-1}}\]) when one mole of ice is converted into water at \[0{}^\circ C\]? (The enthalpy change for the conversion of ice to liquid water is \[6.0\text{ }kJ\text{ }mo{{l}^{-1}}\] at \[0{}^\circ C\]) [AIPMT 2003]
question_answer23) If the bond energies of \[H-H,\,\,Br-Br\] and\[H-Br\] are 433, 192 and 364 kJ \[mo{{l}^{-1}}\] respectively, then \[\Delta {{H}^{0}}\] for the reaction\[{{H}_{2}}(g)+B{{r}_{2}}(g)\xrightarrow[{}]{{}}2HBr(g)\] is: [AIPMT (S) 2004]
question_answer24) Standard enthalpy and standard entropy changes for the oxidation of ammonia at 298 K are\[-382.64\,KJ\,mo{{l}^{-1}}\] and \[-145.6\,J{{K}^{-1}}\,mo{{l}^{-1}},\] respectively. Standard Gibbs energy change for the same reaction at 298 K is: [AIPMT (S) 2004]
question_answer27) The work done during the expansion of a gas from a volume of \[4\,d{{m}^{3}}\] to \[6\,d{{m}^{3}}\] against a constant external pressure of 3 atm, is: [AIPMT (S) 2004]
question_answer30) The absolute enthalpy of neutralisation of the reaction: \[MgO(s)+2HCl\,(aq)\,MgC{{l}_{2}}(aq)\] \[+{{H}_{2}}O\,(l)\] will be: [AIPMT (S) 2005]
A)
less than \[-\text{ }57.33\text{ }kJ\text{ }mo{{l}^{-1}}\]
doneclear
B)
\[-\text{ }57.33\text{ }kJ\text{ }mo{{l}^{-1}}\]
doneclear
C)
greater than \[-\text{ }57.33\text{ }kJ\text{ }mo{{l}^{-1}}\]
question_answer32) Identify the correct statement for change of Gibbs energy for a system \[(\Delta {{G}_{system}})\] at constant temperature and pressure: [AIPMT (S) 2006]
A)
If \[\Delta {{G}_{\text{system}}}>0,\] the process is spontaneous
doneclear
B)
If \[\Delta {{G}_{\text{system}}}=0,\] the system has attained equilibrium
doneclear
C)
If \[\Delta {{G}_{\text{system}}}=0,\] the system is still moving in a particular direction
doneclear
D)
If \[\Delta {{G}_{\text{system}}}<0,\] the process is not spontaneous
question_answer34) The enthalpy and entropy change for the reaction: \[B{{r}_{2}}(l)+C{{l}_{2}}(g)\to 2BrCl(g)\] are \[30\,\,kJ\,\,mo{{l}^{-1}}\] and \[105\,\,k{{J}^{-1}}\,\,mo{{l}^{-1}}\] respectively. The temperature at which the reaction will be in equilibrium is: [AIPMT (S) 2006]
question_answer38) Given that bond energies of \[H-H\] and \[Cl-Cl\] are \[430\text{ }kJ\text{ }mo{{l}^{-1}}\] and \[240\text{ }kJ\text{ }mo{{l}^{-1}}\] respectively and \[\Delta {{H}_{f}}\] for \[HCl\] is \[-90\text{ }kJ\text{ }mo{{l}^{-1}}\]. Bond enthalpy' of \[HCl\] is: [AIPMT (S) 2007]
question_answer42) For the gas phase reaction, \[PC{{l}_{5}}_{(g)}PC{{l}_{3}}(g)+C{{l}_{2}}(g)\] which of the following conditions are correct? [AIPMT (S) 2008]
question_answer43) What volume of .oxygen gas \[({{O}_{2}})\] measured at \[{{0}^{o}}C\] and 1 atm, is needed to bum completely \[1\,L\] of propane gas \[({{C}_{3}}{{H}_{8}})\] measured under the same conditions? [AIPMT (S) 2008]
question_answer44) Bond dissociation enthalpy of \[{{H}_{2}},C{{l}_{2}}\] and \[HCl\] are 434, 242 and 431 kJ \[mo{{l}^{-1}}\] respectively. Enthalpy of formation of HCl is [AIPMT (S) 2008]
The dissociation equilibrium of a gas \[A{{B}_{2}}\] can be represented as [AIPMT (S) 2008]
\[2A{{B}_{2}}(g)2AB(g)+{{B}_{2}}(g)\]
The degree of dissociation is \['x'\] and is small compared to 1. The expression relating the degree of dissociation \[(x)\] with equilibrium constant \[{{K}_{p}}\] and total pressure p is
From the following bond energies: [AIPMT (S) 2009]
\[H-H\] bond energy: 431.37 kJ \[mo{{l}^{-1}}\]
\[C=O\] bond energy: 606.10 kJ \[mo{{l}^{-1}}\]
\[C-C\] bond energy: 336.49 kJ \[mo{{l}^{-1}}\]
\[C-H\] bond energy: 410.50 kJ \[mo{{l}^{-1}}\]
Enthalpy for the reaction,
\[\underset{\begin{smallmatrix} | \\ H \end{smallmatrix}}{\overset{\begin{smallmatrix} H \\ | \end{smallmatrix}}{\mathop{C}}}\,=\underset{\begin{smallmatrix} | \\ H \end{smallmatrix}}{\overset{\begin{smallmatrix} H \\ | \end{smallmatrix}}{\mathop{C}}}\,+H-\xrightarrow{{}}H-\underset{\begin{smallmatrix} | \\ H \end{smallmatrix}}{\overset{\begin{smallmatrix} H \\ | \end{smallmatrix}}{\mathop{C}}}\,-\underset{\begin{smallmatrix} | \\ H \end{smallmatrix}}{\overset{\begin{smallmatrix} H \\ | \end{smallmatrix}}{\mathop{C}}}\,-H\] will be
question_answer49) The values of \[\Delta H\] and \[\Delta S\] for the reaction, \[{{C}_{(\text{graphits)}}}+C{{O}_{2}}(g)\xrightarrow[{}]{{}}\,2\,CO\,(g)\] are 170 kJ and \[170\,J{{K}^{-1}},\] respectively. This reaction will be spontaneous at [AIPMT (S) 2009]
question_answer50) The energy absorbed by each molecule \[({{A}_{2}})\] of a substance is \[4.4\times {{10}^{-19}}\,J\] and bond energy per molecule is \[4.0\times {{10}^{-19}}\,J\]. The kinetic energy of the molecule per atom will be [AIPMT (S) 2009]
question_answer51) For an endothermic reaction, energy of activation is \[{{E}_{a}}\] and enthalpy of reaction is \[\Delta H\] (both of these in kJ/mol). Minimum value of \[{{E}_{a}}\] will be [AIPMT (S) 2010]
question_answer52) Standard entropies of \[{{X}_{2}},{{Y}_{2}}\] and \[X{{Y}_{3}}\] are 60, 40 and \[50\,J\,{{K}^{-1}}\,mo{{l}^{-1}}\] respectively. For the reaction \[\frac{1}{2}{{X}_{2}}+\frac{3}{2}{{Y}_{2}}X{{Y}_{3}};\Delta H=-30kJ,\] to be at equilibrium, the temperature should be [AIPMT (S) 2010]
question_answer55) For vaporisation of water at 1 atm pressure, the values of \[\Delta H\] and \[\Delta S\] are \[40.63\,kJ\,mo{{l}^{-1}}\] and \[108.8\,J{{K}^{-1}}\,mo{{l}^{-1}}\], respectively. The temperature when Gibbs energy change \[(\Delta G)\] for this transformation will be zero, is [AIPMT (M) 2010]
question_answer57) If the enthalpy change for the transition of liquid water to steam is \[30\,kJ\,mo{{l}^{-1}}\] at \[{{27}^{o}}C,\] the entropy change for the process would be [AIPMT (S) 2011]
question_answer61) In which of the following reactions, standard reaction entropy changes \[(\Delta {{S}^{o}})\] is positive and standard Gibb's energy change \[(\Delta {{S}^{o}})\] decreases sharply with increasing temperature? [AIPMT (S) 2012]
question_answer63) Standard enthalpy of vaporization \[{{\Delta }_{vap}}{{H}^{\Theta }}\] for water at \[{{100}^{o}}C\] is \[40.66\,kJ\,mo{{l}^{-1}}\]. The internal energy of vaporisation .of water at \[{{100}^{o}}C\] (in kJ \[mo{{l}^{-1}}\] is (Assume water vapour to behave like an ideal gas). [AIPMT (S) 2012]
question_answer64) Equal volumes of two monoatomic gases, A and B, at same temperature and pressure are mixed. The ratio of specific heats \[(cp/cv)\] of the mixture will be [AIPMT (M) 2012]
The potential difference needed for the electrolytic reduction of aluminium oxide \[(A{{l}_{2}}{{O}_{3}})\] at \[{{500}^{o}}C\] is at least [AIPMT (M) 2012]
question_answer71) The heat of combustion of carbon to \[C{{O}_{2}}\] is \[-393.5\,\,kJ/mol\]. The heat released upon the formation of 35.2 g of \[C{{O}_{2}}\] from carbon and oxygen gas is [NEET 2015 (Re)]
The formation of the oxide ion \[{{O}^{2-}}(g),\] from oxygen atom requires first an exothermic and then an endothermic step as shown below, [NEET 2015 (Re)]
Thus, process of formation of \[{{O}^{2-}}\] in gas phase is unfavourable even though \[{{O}^{2-}}\] is isoelectronic with neon. It is due to the fact that
A)
electron repulsion outweighs the stability gained by achieving noble gas configuration
doneclear
B)
\[{{O}^{-}}\] ion has comparatively smaller size than oxygen atom
doneclear
C)
Oxygen is more electronegative
doneclear
D)
addition of electron in oxygen result in large size of the ion
question_answer75) A gas is allowed to expand in a well-insulated container against a constant external pressure of 2.5 atm from an initial volume of 2.50 L to a final volume of 4.50 L. The change in internal energy \[\Delta U\] of the gas in joules will be [NEET-2017]
question_answer76) For a given reaction, \[\Delta H=35.5\,kJ\,mo{{l}^{-1}}\] and \[\Delta S=83.6\,J{{K}^{-1}}\,mo{{l}^{-1}}.\] The reaction is spontaneous at : (Assume that \[\Delta H\] and \[\Delta S\] do not vary with temperature) [NEET-2017]
question_answer77) The bond dissociation energies of \[{{\text{X}}_{\text{2}}}\text{,}{{\text{Y}}_{\text{2}}}\] and \[\text{XY}\] are in the ratio of 1 : 0.5 : 1. \[\Delta \text{H}\] for the formation of XY is \[\text{--200 kJ mo}{{\text{l}}^{\text{--1}}}\]. The bond dissociation energy of \[{{\text{X}}_{\text{2}}}\] will be [NEET - 2018]
question_answer79) Under isothermal condition, a gas at 300 K expands from 0.1 L to 0.25 L against a constant external pressure of 2 bar. The work done by the gas is [Given that 1 L bar = 100 J] [NEET 2019]