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question_answer1)
Chemical adsorption
A)
increases with increase in temperature done
clear
B)
decreases with increase in temperature done
clear
C)
First increases then decreases with increase in temperature done
clear
D)
First decreases then increases with increase in temperature done
clear
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question_answer2)
The given graphs/data I, II, III and IV represent General trends observed for different physisorption and chemisorption processes under mild conditions of temperature and pressure. Which of the following choices about I, II, III and IV are correct?
A)
I is physisorption and II is chemisorption done
clear
B)
I is physisorption and III is chemisorption done
clear
C)
IV is chemisorption and III is chemisorption done
clear
D)
IV is physisorption and III is chemisorption done
clear
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question_answer3)
In the Freundlich adsorption isotherm, \[\log \left( \frac{x}{m} \right)=\log k+\frac{1}{n}\log p\], the value of n is
A)
any value from 0 to 1 done
clear
B)
a positive integer done
clear
C)
a negative integer done
clear
D)
a positive or a negative fractional number done
clear
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question_answer4)
For an adsorption of \[{{H}_{2}}\] on Ni surface \[Ni\left( s \right)+{{H}_{2}}\left( s \right)\to \] adsorbed \[{{H}_{2}}\] on Ni surface Variation of adsorption with temperature is shown in figure. This indicates that
A)
it is an exothermic change done
clear
B)
it is physical adsorption done
clear
C)
Both [a] and [b] done
clear
D)
None of the. Above done
clear
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question_answer5)
I, II and III are three adsorption isotherm at three temperatures\[{{T}_{1}}\], \[{{T}_{2}}\]and \[{{T}_{3}}\] where x is the amount of adsorbate adsorbed on m g of the adsorbent. Temperatures \[{{T}_{1}}\], \[{{T}_{2}}\] and \[{{T}_{3}}\] are in the order
A)
\[{{T}_{1}}<{{T}_{2}}<{{T}_{3}}\] done
clear
B)
\[{{T}_{1}}={{T}_{2}}={{T}_{3}}\] done
clear
C)
\[{{T}_{3}}<{{T}_{2}}<{{T}_{1}}\] done
clear
D)
No specific order done
clear
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question_answer6)
Methylene blue in aqueous solution, is adsorbed on activated charcoal at\[25{}^\circ C\]. For this process, the correct statement is
A)
The adsorption is accompanied by a decrease in enthalpy done
clear
B)
The adsorption requires activation at \[25{}^\circ C\] done
clear
C)
The adsorption increases with increases of temperature done
clear
D)
The adsorption is irreversible done
clear
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question_answer7)
Select the correct observation in the following isotherm: (where \[\frac{x}{m}\]= amount of the adsorbat adsorbed per gram m of the adsorbent)
A)
\[\left( \frac{x}{m} \right)\propto p{}^\circ \] when point (x) is reached done
clear
B)
Desorption may start along XY done
clear
C)
\[\left( \frac{x}{m} \right)\propto \,{{(p)}^{1/n}}\]along OX done
clear
D)
All of the above done
clear
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question_answer8)
Select the correct statement(s)
A)
A hydrophilic colloid is a colloid is which there is a strong attraction between the dispersed phase and water done
clear
B)
A hydrophobic colloid is a colloid in which there is a lack of attraction between the dispersed phase and water done
clear
C)
Hydrophobic sols are often formed when a solid crystallizes rapidly from a chemical reaction or a supersaturated solution done
clear
D)
All of the above done
clear
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question_answer9)
Some of the properties given below are for colloidal sols. |
(I) Viscosity is same as that of the medium. |
(II) Extensive hydration takes place. |
(III) Migration of the particles under electric field. |
(IV) Particles cannot be detected even under ultramicroscope properties applicable for lyophilic and lyophobic colloidal sols are |
A)
B)
C)
D)
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question_answer10)
Bredig's are method cannot be used to prepare colloidal solution of which of the following metal?
A)
pt done
clear
B)
Fe done
clear
C)
Ag done
clear
D)
Au done
clear
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question_answer11)
Which of the following mixture will lead to the formation of negatively charged colloid
?
A)
\[50\text{ }ml\text{ }of\text{ }0.1\text{ }M\,AgN{{O}_{3}}+\text{ }50\text{ }ml\text{ }of\text{ }0.1\text{ }M\text{ }KI\] done
clear
B)
\[50\text{ }ml\text{ }of\text{ }0.1\text{ }M\,AgN{{O}_{3}}+\text{ }50\text{ }ml\text{ }of\text{ }0.2\text{ }M\text{ }KI\] done
clear
C)
\[50\text{ }ml\text{ }of\text{ }0.2\text{ }M\,AgN{{O}_{3}}+\text{ }50\text{ }ml\text{ }of\text{ }0.1\text{ }M\text{ }KI\] done
clear
D)
\[50\text{ }ml\text{ }of\text{ }0.2\text{ }M\,AgN{{O}_{3}}+\text{ }50\text{ }ml\text{ }of\text{ }0.2\text{ }M\text{ }KI\] done
clear
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question_answer12)
A reddish brown sol is obtained by adding small quantity of \[FeC{{l}_{3}}\]solution to freshly prepared and well washed \[Fe{{(OH)}_{3}}\] ppt. fixed layer and mobile layer are represented as
A)
\[\left[ FeC{{l}_{3}} \right]F{{e}^{3+}}\] \[O{{H}^{-}}\] done
clear
B)
\[\left[ Fe{{(OH)}_{3}} \right]F{{e}^{3+}}\] \[C{{I}^{-}}\] done
clear
C)
\[\left[ Fe{{(OH)}_{3}} \right]F{{e}^{3+}}\] \[3C{{I}^{-}}\] done
clear
D)
\[\left[ FeC{{l}_{3}} \right]F{{e}^{3+}}\] \[3O{{H}^{-}}\] done
clear
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question_answer13)
A sol has positively charged colloidal particles. Which of the following solutions is required in lowest concentration for coagulation?
A)
NaCl done
clear
B)
\[{{K}_{4}}[Fe{{(CN)}_{6}}]\] done
clear
C)
\[ZnC{{l}_{2}}\] done
clear
D)
\[N{{a}_{2}}S{{O}_{4}}\] done
clear
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question_answer14)
Gold number of some lyophilic sols are:
I | : | Casein | : | 0.01 |
II | : | Haemoglobin | : | 0.03 |
III | : | Gum Arabic | : | 0.15 |
V | : | Sodium oleate | : | 0.40 |
Which has maximum protective power?
A)
I done
clear
B)
II done
clear
C)
III done
clear
D)
IV done
clear
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question_answer15)
Milk can be preserved by adding a few drops of
A)
Formic acid solution done
clear
B)
formaldehyde solution done
clear
C)
Acetic acid solution done
clear
D)
Acetaldehyde solution done
clear
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question_answer16)
Which of the following reactions leads to the formation of a substance in the colloidal state?
A)
\[Cu+HgC{{l}_{2}}\to CuC{{l}_{2}}+Hg\] done
clear
B)
\[2HN{{O}_{3}}+3{{H}_{2}}S\to 3S+4{{H}_{2}}O+2NO\] done
clear
C)
\[2Mg+C{{O}_{2}}\to 2MgO+C\] done
clear
D)
\[Cu+CuC{{l}_{2}}\to C{{u}_{2}}C{{l}_{2}}\] done
clear
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question_answer17)
Identify the correct statement regarding enzymes:
A)
Enzymes are specific biological catalysts that well-defined active sites done
clear
B)
Enzymes are normally heterogeneous catalysts that are very specific in their action done
clear
C)
Enzymes are specific biological catalyst that cannot be poisoned done
clear
D)
Enzymes are specific biological catalyst that can normally function at very high temperature (T=1000K) done
clear
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question_answer18)
In Langmuir?s model of adsorption of gas on a solid surface
A)
The mass of gas striking a given area of surface is independent of the pressure of the gas done
clear
B)
The rate of dissociation of adsorbed molecules from the surface does not depend on the surface covered done
clear
C)
The adsorption at a single site on the surface may involve multiple molecules at the same time done
clear
D)
The mass of the gas striking a given area of surface is proportional to the pressure of the gas done
clear
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question_answer19)
Gold number of protective colloids A, B, and D are 0.50, 0.01, 0.1, and 0.005 respectively. The correct order of their protective power is
A)
D<A<C<B done
clear
B)
C<B<D<A done
clear
C)
A<C<B<D done
clear
D)
B<D<A<C done
clear
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question_answer20)
3 g of activated charcoal was added to 50 mL of acetic acid solution (0.06N) in a flask. After an hour it was filtered and the strength of the filtrate was found to be 0.042 N. The amount of acetic acid adsorbed (per gram of charcoal) is
A)
15 mg done
clear
B)
36 mg done
clear
C)
42 mg done
clear
D)
54 mg done
clear
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question_answer21)
Calculate the surface area of a catalyst (in terms of\[{{10}^{3}}c{{m}^{2}}\]) that adsorbs \[{{10}^{3}}c{{m}^{2}}\] of nitrogen reduced to STP per gram in order to from the monolayer. The effective area occupied by \[{{N}_{2}}\]molecule on the surface is \[1.62\times {{10}^{-15}}c{{m}^{2}}\]
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question_answer22)
A cationic colloidal electrolyte forms micelle at \[{{10}^{-4}}\]M concentration in water. If I \[m{{m}^{3}}\]solution contains \[{{10}^{12}}\] micelle structure, then the no. of cations involved in one micelle are\[X\times 10\]. Find the value of X.
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question_answer23)
0.004 mol of \[[PbCr{{O}_{4}}]P{{b}^{2+}}\]colloidal sol is coagulated by x mL. of 1 M KI what is the value of x?
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question_answer24)
The chemisorption of \[{{H}_{2}}\]on an activated surface becomes 40% faster if temperature is raised from 500 K to 1000 K. Calculate energy of activation to the nearest possible integer.
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question_answer25)
In \[C{{S}_{2}}\] sulphur atoms are associated to form colloidal sol. 2.56 g of sulphur colloidal sol in 100 g \[C{{S}_{2}}\]shows osmotic pressure of 2.463 atm at 300 K. how many sulphur atoms are associated in colloidal sol? (Solution constant = 0.0821 L atm\[mo{{l}^{-1}}{{K}^{-1}}\])
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