# JEE Main

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

## Mathematics

Equilibrium

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Q 1. The equilibrium constant of a reaction is {tex} 20.0 . {/tex} At equilibrium, the rate constant of forward reaction is {tex} 10.0 . {/tex} The rate constant for backward reaction is

0.5

B

20

C

10

D

200

##### Explanation

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Q 2. At a given temperature, the equilibrium constant for the reactions
{tex} \mathrm { NO } ( \mathrm { g } ) + \frac { 1 } { 2 } \mathrm { O } _ { 2 } ( \mathrm { g } ) \rightleftharpoons \mathrm { NO } _ { 2 } ( \mathrm { g } ) {/tex} and {tex}2 \mathrm { NO } _ { 2 } ( \mathrm { g } ) \rightleftharpoons {/tex} {tex} 2 \mathrm { NO } ( \mathrm { g } ) + \mathrm { O } _ { 2 } ( \mathrm { g } ) {/tex} are {tex}\mathrm K _ { 1 } {/tex} and {tex}\mathrm K _ { 2 } {/tex} respectively.
If {tex}\mathrm K _ { 1 } {/tex} is {tex} 4\times 10 ^ { - 3 } , {/tex} then {tex}\mathrm K _ { 2 } {/tex} will be

A

{tex} 8 \times 10 ^ { - 3 } {/tex}

B

{tex} 16 \times 10 ^ { - 3 } {/tex}

{tex} 6.25 \times 10 ^ { 4 } {/tex}

D

{tex} 6.25 \times 10 ^ { 6 } {/tex}

##### Explanation

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Q 3. In which of the following reactions {tex}\mathrm{ K _ { P } > K _ { C }} ? {/tex}

A

{tex} \mathrm { N } _ { 2 } ( \mathrm { g } ) + 3 \mathrm { H } _ { 2 } ( \mathrm { g } ) \rightleftharpoons 2 \mathrm { NH } _ { 3 } ( \mathrm { g } ) {/tex}

B

{tex} \mathrm { H } _ { 2 } ( \mathrm { g } ) + \mathrm { I } _ { 2 } ( \mathrm { g } ) \rightleftharpoons 2 \mathrm { HI } ( \mathrm { g } ) {/tex}

C

{tex} \mathrm { PCl } _ { 3 } ( \mathrm { g } ) + \mathrm { Cl } _ { 2 } ( \mathrm { g } ) \rightleftharpoons \mathrm { PCl } _ { 5 } ( \mathrm { g } ) {/tex}

{tex} 2 \mathrm { SO } _ { 3 } ( \mathrm { g } ) \rightleftharpoons 2 \mathrm { SO } _ { 2 } ( \mathrm { g } ) + \mathrm { O } _ { 2 } ( \mathrm { g } ) {/tex}

##### Explanation

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Q 4. At {tex} 1000 \mathrm { K } , {/tex} the value of {tex} \mathrm K _ {\mathrm p } {/tex} for the reaction {tex} \mathrm { PCl } _ { 5 } \rightleftharpoons {/tex} {tex} \mathrm { PCl } _ { 3 } + \mathrm { Cl } _ { 2 } {/tex} is {tex} 20 \mathrm { R } , {/tex} then {tex} \mathrm K _ {\mathrm C } {/tex} will be

A

0.04

0.02

C

0.01

D

0.03

##### Explanation

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Q 5. For the reaction {tex} \mathrm { N } _ { 2 } \mathrm { O } _ { 4 } \rightleftharpoons 2 \mathrm { NO } , {/tex} degree of dissociation is {tex} \alpha {/tex} . The number of moles at equilibirum will be

A

{tex} ( 1 - \alpha ) ^ { 2 } {/tex}

{tex} ( 1 + \alpha ) {/tex}

C

3

D

1

##### Explanation

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Q 6. {tex}4{/tex} mole of {tex}\mathrm A {/tex} are mixed with {tex}4{/tex} mole of {tex}\mathrm B , {/tex} when {tex}2{/tex} mole of {tex}\mathrm C {/tex} are formed at equilibrium according to the reaction, {tex}\mathrm A +\mathrm B \rightleftharpoons \mathrm C +\mathrm D . {/tex} The equilibrium constant is

A

4

1

C

{tex} \sqrt { 2 } {/tex}

D

{tex} \sqrt { 4 } {/tex}

##### Explanation

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Q 7. {tex}6{/tex} gram hydrogen reacts with {tex} 9.023 \times 10 ^ { 23 } {/tex} chlorine molecules to form {tex} \mathrm { HCl } {/tex}. If total pressure of the reaction is {tex}800 \mathrm { mm } {/tex} then what will be the partial pressure of {tex} \mathrm { HCl } {/tex} ?

A

400{tex} \mathrm { mm } {/tex}

533{tex} \mathrm { mm } {/tex}

C

600{tex} \mathrm { mm } {/tex}

D

153.3{tex} \mathrm { mm } {/tex}

##### Explanation

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Q 8. {tex}20 \% {/tex} part of {tex} \mathrm { N } _ { 2 } \mathrm { O } _ { 4 } {/tex} is dissociated in {tex} \mathrm { NO } _ { 2 } {/tex} at {tex}1{/tex} atmospheric pressure. What is the value of {tex} \mathrm K _ { \mathrm p } ? {/tex}

A

0.29

B

16

C

1.6

None of these

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Q 9. Vaporisation of one mole of {tex} \mathrm { PCl } _ { 5 } {/tex} is done in a {tex} \mathrm {1 L } {/tex} container. If {tex}0.2{/tex} mole {tex} \mathrm { Cl } _ { 2 } {/tex} is formed at equilibrium, then what will be the value of equilibrium constant?

A

0.15

0.05

C

1.78

D

0.2

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Q 10. The equilibrium constant {tex}\mathrm K _ {\mathrm c } {/tex} for {tex} \mathrm A _ { ( \mathrm g ) } \rightleftharpoons \mathrm B _ { (\mathrm g ) } {/tex} is {tex}1.1{/tex} means

A

{tex} [ \mathrm { A } ] \mathrm { eq } > [ \mathrm { B } ] \mathrm { eq } {/tex}

{tex} [ \mathrm { Aeq } ] < [ \mathrm { B } ] \mathrm { eq } {/tex}

C

{tex} [ \mathrm { Aeq } ] = 1.1 \mathrm { M } {/tex}

D

{tex} [ \mathrm { Beq } ] = 1.1 \mathrm { M } {/tex}

##### Explanation

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Q 11. Which of the following is not Lewis acid?

A

B

C

##### Explanation

All jother can accept electrons. in not electron deficient.

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Q 12. Which of the following is conjugate acid of ?

B

C

D

##### Explanation

Conjugate acid of is

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Q 13. Which of the following species can act both as acid as well as a base?

A

C

D

##### Explanation

can accept or give a proton.

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Q 14. Which of the following salts will give basic solution on hydrolysis?

A

B

KCl

D

##### Explanation

KOH⟶ (Basic solution),

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Q 15. Which of the following salts with a concentration M will give a basic solution?

A

Ammonium acetate

B

Ammonium chloride

C

Ammonium sulphate

Sodium acetate

##### Explanation

NaOH (Basic solution) ,

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Q 16. The yield of in the the reaction is affected by

A

Change in pressure and temperature

B

Change in temperature and concentration of

C

Change in pressure and concentration of

Change in pressure, temperature and concentration of

##### Explanation

The reaction is exothermic accompanied with decrease in number of moles. So, the equilibrium is affected by temperature, pressure and concentration.

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Q 17. According to Lewis concept, an acid is a/an

A

Proton donor

B

Electron pair donor

C

Proton acceptor

Electron pair acceptor.

##### Explanation

Lewis acid is acceptor of a pair of electrons while lewis base is donor of a pair of electons.

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Q 18. What will be the ionisation constant of formic acid if its 0.001 M solution is 14.5% ionised?

B

C

D

##### Explanation

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Q 19. What is the percentage dissociation of M solution of acetic acid? .

A

10%

B

100%

1%

D

##### Explanation

or
% dissociation,

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Q 20. For a polybasic acid, the dissociation constants have a different values for each step, e.g.,

What is the observed trend of dissociation constants in successive stages?

B

C

D

##### Explanation

The values of dissociation constants for successive stages decrease.

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Q 21. mole of NaOH is added to 5 litres of water. What will be the pH of the solution?

12

B

7

C

2

D

10

##### Explanation

Conc. Of NaOH, or

= 12

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Q 22. What will be the pH of a soft drink if hydrogen ion concentration in sample is M?

A

B

D

##### Explanation

pH = - log

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Q 23. What is pOH of an aqueous solution with hydrogen ion concentration equal to ?

B

C

D

##### Explanation

pOH = 14 - pH, 14 -

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Q 24. Which of the following salts does not show is correct nature mentioned against it?

A

KBr solution - Neutral

NaCN solution - Acidic

C

solution- acidic

D

KF solution - Basic

##### Explanation

NaCN solution is basic in nature since HCN formed is a weak acid and does not hydrolyse.

NaOH ⟶ (Basic solution)

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Q 25. The degree of ionisation of an acid HA is at M concentratin. Its. Dissociation constant will be

A

C

D