JEE Main > Surface Chemistry

Explore popular questions from Surface Chemistry for JEE Main. This collection covers Surface Chemistry previous year JEE Main questions hand picked by popular teachers.


Q 1.    

Correct4

Incorrect-1

Which one of the following characteristics is not correct for physical adsorption?

A

Adsorption on solids is reversible

Adsorption increases with increase in temperature

C

Adsorption is spontaneous

D

Both enthalpy and entropy of adsorption are negative.

Explanation

Q 2.    

Correct4

Incorrect-1

The volume of a colloidal particle, {tex} V _ { c } {/tex} as compared to the volume of a solute particle in a true solution {tex} V _ { \text {s } } {/tex} could be

A

{tex} \sim 1 {/tex}

B

{tex} \sim 10 ^ { 23 } {/tex}

C

{tex} \sim 10 ^ { - 3 } {/tex}

{tex} \sim 10 ^ { 3 } {/tex}

Explanation



Q 3.    

Correct4

Incorrect-1

The disperse phase in colloidal iron {tex}\mathrm{(III)}{/tex} hydroxide and colloidal gold is positively and negatively charged, respectively. Which of the following statements is {tex}\mathrm{NOT}{/tex} correct?

A

Magnesium chloride solution coagulates, the gold sol more readily than the iron {tex}\mathrm{(III)}{/tex} hydroxide sol

B

Sodium sulphate solution causes coagulation in both sols

Mixing of the sols has no effect

D

Coagulation in both sols can be brought about by electrophoresis

Explanation


Q 4.    

Correct4

Incorrect-1

In Langmuir's model of adsorption of a gas on a solid surface

A

the rate of dissociation of adsorbed molecules from the surface does not depend on the surface covered

B

the adsorption at a single site on the surface may involve multiple molecules at the same time

the mass of gas striking a given area of surface is proportional to the pressure of the gas

D

the mass of gas striking a given area of surface is independent of the pressure of the gas.

Explanation


Q 5.    

Correct4

Incorrect-1

Which is an incorrect statement?

A

Heat of physical adsorption is {tex} 20 - 40 \mathrm { kJ } \ \mathrm {mol} ^{-1}{/tex}

B

Chemical adsorption is specific in nature

C

Physical adsorption is reversible

Physical adsorption takes place at very high temperature

Explanation

Q 6.    

Correct4

Incorrect-1

Which gas is adsorbed easily at solid surface?

{tex} \mathrm { SO } _ { 2 } {/tex}

B

{tex} \mathrm { H } _ { 2 } {/tex}

C

{tex} \mathrm {O} _ { 2 } {/tex}

D

{tex} \mathrm { N } _ { 2 } {/tex}

Explanation

Q 7.    

Correct4

Incorrect-1

Rate of adsorption of gas is greater when pressure increased

For low range of pressure

B

For high range of pressure

C

For moderate range of pressure

D

For every range of pressure

Explanation

Q 8.    

Correct4

Incorrect-1

For Freundlich adsorption isotherm which is a correct graph?

A

C

D

Explanation

Q 9.    

Correct4

Incorrect-1

For Langmuir adsorption isotherm, which is correct?

A

B

C

None of these

Explanation

Q 10.    

Correct4

Incorrect-1

Which is not an application of adsorption?

Purification of water by its exchange

B

To create vacuum

C

Chromatographic analysis

D

Artificial rain

Explanation

Q 11.    

Correct4

Incorrect-1

Which method of preparation of sol involves chemical reaction?

Hydrolysis

B

Mechanical dispersion

C

Exchange of solvent

D

All of these

Explanation

Q 12.    

Correct4

Incorrect-1

At a certain value of pH, amino acid does not migrate towards any of the electrode under the influence of electric field. This pH is called

A

Neutralisation point

B

End point

Isoelectric point

D

All of these

Explanation

Q 13.    

Correct4

Incorrect-1

{tex} \mathrm { As } _ { 2 } \mathrm { S } _ { 3 } {/tex} colloidal solution obtained when {tex} \mathrm { As } _ { 2 } \mathrm { O } _ { 3 } {/tex} is saturated with {tex} \mathrm { H } _ { 2 } \mathrm { S } {/tex}. Which is the diffused part?

A

{tex} \mathrm {A S} ^ { + 3 } {/tex}

{tex} \mathrm { S } ^ { - 2 } {/tex}

C

{tex} \mathrm { H } ^ { + } {/tex}

D

{tex} \mathrm {O} ^ { - 2 } {/tex}

Explanation

Q 14.    

Correct4

Incorrect-1

Fixed parts of a colloidal solution of {tex}\mathrm { AgI} {/tex} are respectively {tex}\mathrm {[AgI]I}^-{/tex} and {tex}\mathrm {[AgI] Ag^+} {/tex} in presence of

{tex} \mathrm { KI} {/tex} and {tex} \mathrm { AgNO } _ { 3 } {/tex}

B

{tex} \mathrm { AgNO } _ { 3 } {/tex} and {tex} \mathrm { KI } {/tex}

C

{tex} \mathrm { KI } {/tex} and {tex} \mathrm { KIO } _ { 3 } {/tex}

D

{tex} \mathrm { AgNO } _ { 3 } {/tex} and {tex} \mathrm { Ba } \left( \mathrm { NO } _ { 3 } \right) _ { 2 } {/tex}

Explanation

Q 15.    

Correct4

Incorrect-1

{tex}1{/tex} mol of {tex}\mathrm {[AgI]Ag ^+} {/tex}sol is coagulated by

A

{tex} 100 \ \mathrm { ml } \ 1 \mathrm { M } \ \mathrm { K } _ { 2 } \mathrm { SO } _ { 4 } {/tex}

B

{tex} \mathrm { Fe } ^ { + 3 } {/tex}

C

{tex}1{/tex} mol of {tex}\mathrm {Na}^+{/tex}

None of these

Explanation

Q 16.    

Correct4

Incorrect-1

Which is correctly matched?

A

{tex} \mathrm { ZSM } - 5 - \mathrm { H } _ { \mathrm { x } } \left[ \left( \mathrm { AlO } _ { 2 } \right) _ { \mathrm { x } } \left( \mathrm { SiO } _ { 2 } \right) _ { 96 - \mathrm { x } } \right] .16 \mathrm { H } _ { 2 } \mathrm { O } {/tex}

B

Gemelinite {tex} - \mathrm { Na } _ { 2 } \mathrm { Ca } ( \mathrm { AlO } ) _ { 2 } \left( \mathrm { SiO } _ { 2 } \right) _ { 4 } . 6 \mathrm { H } _ { 2 } \mathrm { O } {/tex}

C

Fauzasite (natural) {tex} - \mathrm { Na } _ { 56 } \left[ \left( \mathrm { Al } _ { 2 } \mathrm { O } \right) _ { 56 } \left( \mathrm { SiO } _ { 2 } \right) _ { 136 } \right].250 \mathrm { H } _ { 2 } \mathrm { O } {/tex}

All of these

Explanation

Q 17.    

Correct4

Incorrect-1

Which is incorrectly matched?

A

B

C

Explanation

Q 18.    

Correct4

Incorrect-1

Which catalyst is used in polymerisation of ethene?

A

{tex} \mathrm { P t }{/tex}

B

{tex} \mathrm { Ni } {/tex}

C

{tex}\mathrm {Zeolites}{/tex}

{tex}\mathrm {Ziegler-Natta\ catalyst}{/tex}

Explanation

Q 19.    

Correct4

Incorrect-1

Gold number of starch is {tex} 25 . {/tex} How much of it is required to prevent coagulation of {tex} 100 \mathrm { ml } {/tex} of gold sol adding {tex} 1 \mathrm { ml } {/tex} of {tex} 10 \% {/tex} {tex} \mathrm {NaCl} {/tex} solution?

A

{tex} 25 \mathrm { mg } {/tex}

{tex} 250 \mathrm { mg } {/tex}

C

{tex} 2.5 \mathrm { mg } {/tex}

D

{tex} 0.250 \mathrm { mg } {/tex}

Explanation

Q 20.    

Correct4

Incorrect-1

Among the following, the surfactant that will form micelles in aqueous solution at the lowest molar concentration at ambient conditions is

{tex} \mathrm { CH } _ { 3 } \left( \mathrm { CH } _ { 2 } \right) _ { 15 } \mathrm { N } ^ { + } \left( \mathrm { CH } _ { 3 } \right) _ { 3 } \mathrm { Br } ^ { - } {/tex}

B

{tex} \mathrm { CH } _ { 3 } \left( \mathrm { CH } _ { 2 } \right) _ { 11 } \mathrm { OSO } _ { 3 } ^{-} \mathrm { Na } ^ { + } {/tex}

C

{tex} \mathrm { CH } _ { 3 } \left( \mathrm { CH } _ { 2 } \right) _ { 6 } \mathrm { COO }^{-} \mathrm { Na } ^ { + } {/tex}

D

{tex} \mathrm { CH } _ { 3 } \left( \mathrm { CH } _ { 2 } \right) _ { 11 } \mathrm { N } ^ { + } \left( \mathrm { CH } _ { 3 } \right) _ { 3 } \mathrm { Br } ^ { - } {/tex}

Explanation

Q 21.    

Correct4

Incorrect-1

Among the electrolytes {tex} \mathrm { Na } _ { 2 } \mathrm { SO } _ { 4 } , \mathrm { CaCl } _ { 2 } , \mathrm { Al } _ { 2 } \left( \mathrm { SO } _ { 4 } \right) _ { 3 } {/tex} and {tex} \mathrm { NH } _ { 4 } \mathrm { Cl } {/tex}, the most effective coagulating agent for {tex} \mathrm { Sb } _ { 2 } \mathrm { S } _ { 3 } {/tex} sol is

A

{tex} \mathrm { Na } _ { 2 } \mathrm { SO } _ { 4 } {/tex}

B

{tex} \mathrm { CaCl } _ { 2 } {/tex}

{tex} \mathrm { Al } _ { 2 } \left( \mathrm { SO } _ { 4 } \right) _ { 3 } {/tex}

D

{tex} \mathrm { NH } _ { 4 } \mathrm { Cl } {/tex}

Explanation

Q 22.    

Correct4

Incorrect-1

Methylene blue, from its aqueous solution, is adsorbed on activated charcoal at {tex} 25 ^ { \circ } \mathrm { C } {/tex}. For this process, the correct statement is

A

The adsorption requires activation at {tex} 25 ^ { \circ } \mathrm { C } {/tex}

The adsorption is accompanied by a decrease in enthalpy

C

The adsorption increases with increase of temperature

D

The adsorption is irreversible

Explanation

Q 23.    

Correct4

Incorrect-1

The qualitative sketches {tex} \mathrm {I,\ II} {/tex} and {tex} \mathrm {III} {/tex} given below show the variation of surface tension with molar concentration of three different aqueous solutions of {tex} \mathrm { KCl } , \mathrm { CH } _ { 3 } \mathrm { OH } {/tex} and {tex} \mathrm { CH } _ { 3 } \left( \mathrm { CH } _ { 2 } \right) _ { 11 } \mathrm { OSO } _ { 3 }^{-} \mathrm {Na }^+{/tex} at room temperature. The correct assignment of the sketches is

A

{tex} \begin{array} { l l } { \text { I: KCl } } & { \text { II } : \mathrm { CH } _ { 3 } \mathrm { OH } } & { \text { III }: \mathrm { CH } _ { 3 } \left( \mathrm { CH } _ { 2 } \right) _ { 11 }\mathrm{ OSO } _ { 3 }^{-} \mathrm { Na } ^ { + } } \end{array} {/tex}

B

{tex} \mathrm { I }: \mathrm { CH } _ { 3 } \left( \mathrm { CH } _ { 2 } \right) _ { 11 } \mathrm { OSO } _ { 3 }^ {-} {\mathrm { Na } ^ { + } } \quad \mathrm { II }: \mathrm { CH } _ { 3 } \mathrm { OH } \quad \mathrm { III }: \mathrm { KCl } {/tex}

C

{tex} \begin{array} { l l } { \text { I: KCl } } & { \text { II } : \mathrm { CH } _ { 3 } \left( \mathrm { CH } _ { 2 } \right) _ { 11 } \mathrm { OSO } _ { 3 }^ - \mathrm { Na } ^ { + } } & { \text { III }:\mathrm{{ CH } _ { 3 } \mathrm { OH } } } \end{array} {/tex}

{tex}\mathrm I: \mathrm {CH_3} \mathrm {OH} \quad \quad \mathrm {II}:\mathrm {KCl}\quad \quad \mathrm {III}: \mathrm {CH_3 (CH_2)_{11}OSO_3^{-}Na^+}{/tex}

Explanation

Q 24.    

Correct4

Incorrect-1

The formation of micelles(Associated colloids) takes place

A

above {tex} \mathrm { CMC } {/tex} and at kraft temperature.

B

at {tex}\mathrm{CMC}{/tex} and above kraft temperature.

C

at {tex} \mathrm{CMC}{/tex} and at kraft temperature.

above {tex} \mathrm{CMC}{/tex} and above kraft temperature.

Explanation

Q 25.    

Correct4

Incorrect-1

Which of the following is an example of positively charged sols?

A

{tex} \mathrm { As } _ { 2 } \mathrm { S } _ { 3 } {/tex}

B

Gold sol

C

Congo red sol

Haemoglobin

Explanation