NEET > Surface Chemistry

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


Q 1.    

Correct4

Incorrect-1

Which one of the following statements is not correct?

The value of equilibrium constant is changed in the presence of a catalyst in the reaction at equilibrium.

B

Enzymes catalyse mainly bio-chemical reactions.

C

Coenzymes increase the catalytic activity of enzyme.

D

Catalyst does not initiate any reaction.

Explanation


Q 2.    

Correct4

Incorrect-1

The coagulation values in millimoles per litre of the electrolytes used for the coagulation of {tex} \mathrm { As } _ { 2 } \mathrm { S } _ { 3 } {/tex} are given below:
I. {tex} ( \mathrm { NaCl } ) = 52 , {/tex}
II.{tex} \left( \mathrm { BaCl } _ { 2 } \right) = 0.69, {/tex}
III.{tex}\left( \mathrm { MgSO } _ { 4 } \right) = 0.22 {/tex}{tex} \quad {/tex}
The correct order of their coagulating power is

A

{tex} \mathrm { I } > \mathrm { II } > \mathrm { III } {/tex}

B

{tex} \mathrm { II } > \mathrm { I } > \mathrm { III } {/tex}

{tex} \mathrm { III } > \mathrm { II } > \mathrm { I } {/tex}

D

{tex} \mathrm { III } > \mathrm { I } > \mathrm { II } {/tex}

Explanation


Q 3.    

Correct4

Incorrect-1

Fog is a colloidal solution of

A

solid in gas

B

gas in gas

liquid in gas

D

gas in liquid.

Explanation


Q 4.    

Correct4

Incorrect-1

Which one of the following characteristics is associated with adsorption?

A

{tex} \Delta G {/tex} and {tex} \Delta H {/tex} are negative but {tex} \Delta S {/tex} is positive.

B

{tex} \Delta G {/tex} and {tex} \Delta S {/tex} are negative but {tex} \Delta H {/tex} is positive.

C

{tex} \Delta G {/tex} is negative but {tex} \Delta H {/tex} and {tex} \Delta S {/tex} are positive.

{tex} \Delta G , \Delta H {/tex} and {tex} \Delta S {/tex} all are negative.

Explanation


Q 5.    

Correct4

Incorrect-1

Which property of colloidal solution is independent of charge on the colloidal particles?

A

Electro-osmosis

Tyndall effect

C

Coagulation

D

Electrophoresis

Explanation


Q 6.    

Correct4

Incorrect-1

Which property of colloids is not dependent on the charge on colloidal particles?

A

Coagulation

B

Electrophoresis

C

Electro-osmosis

Tyndall effect

Explanation


Q 7.    

Correct4

Incorrect-1

In Freundlich adsorption isotherm, the value of 1{tex} / n {/tex} is

between 0 and 1 in all cases

B

between 2 and 4 in all cases

C

1 in case of physical absorption

D

1 in case of chemisorption.

Explanation


Q 8.    

Correct4

Incorrect-1

Which one of the following statements is incorrect about enzyme catalysis?

A

Enzymes are mostly proteinous in nature.

B

Enzyme action is specific.

C

Enzymes are denatured by ultraviolet rays and at high temperature.

Enzymes are least reactive at optimum temperature.

Explanation


Q 9.    

Correct4

Incorrect-1

The protecting power of lyophilic colloidal sol is expressed in terms of

A

coagulation value

gold number

C

critical micelle concentration

D

oxidation number

Explanation

Q 10.    

Correct4

Incorrect-1

If {tex} x {/tex} is amount of adsorbate and {tex} m {/tex} is amount of adsorbent, which of the following relations is not related to adsorption process?

A

{tex} x / m = f ( p ) {/tex} at constant {tex} T {/tex}

B

{tex} x / m = f ( T ) {/tex} at constant {tex} p {/tex}

C

{tex} p = f ( T ) {/tex} at constant {tex} ( x / m ) {/tex}

{tex} \frac { x } { m } = p \times T {/tex}

Explanation

Q 11.    

Correct4

Incorrect-1

The Langmuir adsorption isotherm is deduced using the assumption

the adsorption sites are equivalent in their ability to adsorb the particles

B

the heat of adsorption varies with coverage

C

the adsorbed molecules interact with each other

D

the adsorption takes place in multilayers.

Explanation


Q 12.    

Correct4

Incorrect-1

A plot of {tex} \log ( x / m ) {/tex} versus {tex} \log p {/tex} for the adsorption of a gas on a solid gives a straight line with slope equal to

A

{tex} \log K {/tex}

B

{tex} - \log K {/tex}

C

{tex}n{/tex}

1{tex} / n {/tex}

Explanation


Q 13.    

Correct4

Incorrect-1

Which one of the following forms micelles in aqueous solution above certain concentration?

Dodecyl trimethyl ammonium chloride

B

Glucose

C

Urea

D

Pyridinium chloride

Explanation

Q 14.    

Correct4

Incorrect-1

The enzyme which hydrolyses triglycerides to fatty acids and glycerol is called

A

maltase

lipase

C

zymase

D

pepsin

Explanation

Q 15.    

Correct4

Incorrect-1

According to the adsorption theory of catalysis, the speed of the reaction increases because

A

the concentration of reactant molecules at the active centres of the catalyst becomes high due to adsorption

B

in the process of adsorption, the activation energy of the molecules becomes large

C

adsorption produces heat which increases the speed of the reaction

adsorption lowers the activation energy of the reaction.

Explanation


Q 16.    

Correct4

Incorrect-1

Position of non polar and polar part in micelle

polar at outer surface but non polar at inner surface

B

polar at inner surface non polar at outer surface

C

distributed over all the surface

D

are present in the surface only.

Explanation


Q 17.    

Correct4

Incorrect-1

Which is not correct regarding the adsorption of a gas on surface of a solid?

On increasing temperature adsorption increases continuously.

B

Enthalpy and entropy change is negative.

C

Adsorption is more for some specific substance.

D

It is a reversible reaction.

Explanation


Q 18.    

Correct4

Incorrect-1

Which one of the following method is commonly used method for destruction of colloid?

A

Dialysis

B

Condensation

C

Filteration by animal membrane

By adding electrolyte

Explanation


Q 19.    

Correct4

Incorrect-1

At the critical micelle concentration {tex} ( \mathrm { CMC } ) {/tex} the surfactant molecules

associate

B

dissociate

C

decompose

D

become completely soluble

Explanation


Q 20.    

Correct4

Incorrect-1

The ability of anion, to bring about coagulation of a given colloid, depends upon

A

magnitude of the charge

both magnitude and charge

C

its charge only

D

sign of the charge alone.

Explanation


Q 21.    

Correct4

Incorrect-1

A colloidal system has particles of which of the following size?

A

{tex} 10 ^ { - 9 } \mathrm { m } {/tex} to {tex} 10 ^ { - 12 } \mathrm { m } {/tex}

{tex} 10 ^ { - 6 } \mathrm { m } {/tex} to {tex} 10 ^ { - 9 } \mathrm { m } {/tex}

C

{tex} 10 ^ { - 4 } \mathrm { m } {/tex} to {tex} 10 ^ { - 10 } \mathrm { m } {/tex}

D

{tex} 10 ^ { - 5 } \mathrm { m } {/tex} to {tex} 10 ^ { - 7 } \mathrm { m } {/tex}

Explanation


Q 22.    

Correct4

Incorrect-1

When a few typical solutes are separated by a particular selective membrane such as protein particles, blood corpuscles, this process is called

A

transpiration

B

endosmosis

dialysis

D

diffusion

Explanation


Q 23.    

Correct4

Incorrect-1

For the adsorption of a gas on a solid, the plot of {tex} \log ( x / m ) {/tex} versus {tex} \log P {/tex} is linear with slope equal to

A

{tex}n{/tex}

{tex}1 / n {/tex}

C

{tex} k {/tex}

D

{tex} \log k {/tex}

Explanation


Q 24.    

Correct4

Incorrect-1

Which of the following statements is not true about the oil-in-water type emulsion?

A

On addition of small amount of water, no separate layer of water appears

B

On addition of oil, separate layer of oil is formed

C

Addition of an electrolyte causes the conductivity of the emulsion to increase

Addition of small amount of oil soluble dye renders the entire emulsion coloured.

Explanation

Q 25.    

Correct4

Incorrect-1

Which of the following is not a favourable condition for physical adsorption?

A

High pressure

B

Negative {tex} \Delta \mathrm { H } {/tex}

C

Higher critical temperature of adsorbate

High temperature

Explanation