JEE Main > Equilibrium

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


Q 1.    

Correct4

Incorrect-1

{tex} \mathrm { 1M\ NaCl } {/tex} and {tex} \mathrm { 1M\ HCl } {/tex} are present in an aqueous solution. The solution is

not a buffer solution with {tex} \mathrm { pH } < 7 {/tex}

B

not a buffer solution with {tex} \mathrm { pH } > 7 {/tex}

C

a buffer solution with {tex} \mathrm { pH } < 7 {/tex}

D

a buffer solution with {tex} \mathrm { pH } > 7 {/tex}

Explanation

Q 2.    

Correct4

Incorrect-1

Species acting as both Bronsted acid and base is

{tex} \left( \mathrm { HSO } _ { 4 } \right) ^ { - 1 } {/tex}

B

{tex} \mathrm { Na } _ { 2 } \mathrm { CO } _ { 3 } {/tex}

C

{tex} \mathrm { NH } _ { 3 } {/tex}

D

{tex} \mathrm { OH } ^ { - 1 } {/tex}

Explanation

Q 3.    

Correct4

Incorrect-1

Let the solubility of an aqueous solution of {tex} \mathrm { Mg } ( \mathrm { OH } ) _ { 2 } {/tex} be {tex} x {/tex} then its {tex} K _ { s p } {/tex} is

{tex}4 x ^ { 3 } {/tex}

B

{tex} 108x ^ { 5 } {/tex}

C

{tex} 27x ^ { 4 } {/tex}

D

{tex}9 x {/tex}

Explanation

Q 4.    

Correct4

Incorrect-1

Change in volume of the system does not alter which of the following equilibria?

B

C

D

Explanation

Q 5.    

Correct4

Incorrect-1

For the reaction {tex} \mathrm { CO } ( \mathrm { g } ) + ( 1 / 2 ) \mathrm { O } _ { 2 } ( \mathrm { g } ) = \mathrm { CO } _ { 2 } ( \mathrm { g } ) , K _ { p } / K _ { c } {/tex} is

A

{tex} R T {/tex}

B

{tex} ( R T ) ^ { - 1 } {/tex}

{tex} ( R T ) ^ { - 1 / 2 } {/tex}

D

{tex} ( R T ) ^ { 1 / 2 } {/tex}

Explanation

Q 6.    

Correct4

Incorrect-1

Which one of the following statements is not true?

A

{tex} \mathrm { pH } + \mathrm { pOH } = 14 {/tex} for all aqueous solutions

The {tex} \mathrm { pH } {/tex} of {tex} 1 \times 10 ^ { - 8 } \mathrm { M\ HCl } {/tex} is 8

C

{tex} 96,500 {/tex} coulombs of electricity when passed through a {tex} CuSO_{4} {/tex}, solution deposits 1 gram equivalent of copper at the cathode

D

The conjugate base of {tex} \mathrm { H } _ { 2 } \mathrm { PO } _ { 4 } ^ { - } {/tex} is {tex} \mathrm { HPO } _ { 4 } ^ { 2 - } {/tex}

Explanation

Q 7.    

Correct4

Incorrect-1

The solubility in water of a sparingly soluble salt {tex} \mathrm { AB } _ { 2 } {/tex} is {tex} 1.0 \times 10 ^ { - 5 } \mathrm { mol } \mathrm { L } ^ { - 1 } {/tex} . Its solubility product number will be

A

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

B

{tex} 1 \times 10 ^ { - 15 } {/tex}

C

{tex} 1 \times 10 ^ { - 10 } {/tex}

{tex} 4 \times 10 ^ { - 15 } {/tex}

Explanation

Q 8.    

Correct4

Incorrect-1

For the reaction equilibrium {tex} \mathrm { N } _ { 2 } \mathrm { O } _ { 4 } ( \mathrm { g } ) \rightleftharpoons 2 \mathrm { NO } _ { 2 } ( \mathrm { g } ) {/tex}
the concentrations of {tex} \mathrm { N } _ { 2 } \mathrm { O } _ { 4 } {/tex} and {tex} \mathrm { NO } _ { 2 } {/tex} at equilibrium are {tex} 4.8 \times 10 ^ { - 2 } {/tex} and {tex} 1.2 \times 10 ^ { - 2 } \mathrm { mol } \mathrm { L } ^ { - 1 } {/tex} respectively. The value of {tex} K _ { \mathrm { c } } {/tex} for the reaction is

A

{tex} 3 \times 10 ^ { - 1 } \mathrm { mol } \mathrm { L } ^ { - 1 } {/tex}

{tex} 3 \times 10 ^ { - 3 } \mathrm { mol } \mathrm { L } ^ { - 1 } {/tex}

C

{tex} 3 \times 10 ^ { 3 } \mathrm { mol } \mathrm { L } ^ { - 1 } {/tex}

D

{tex} 3.3 \times 10 ^ { 2 } \mathrm { mol } \mathrm { L } ^ { - 1 } {/tex}

Explanation

Q 9.    

Correct4

Incorrect-1

Consider the reaction equilibrium
{tex} 2 \mathrm { SO } _ { 2 } ( \mathrm { g } ) + \mathrm { O } _ { 2 } ( \mathrm { g } ) \rightleftharpoons 2 \mathrm { SO } _ { 3 } ( \mathrm { g } ) ; \Delta \mathrm { H } ^ { \circ } = - 198 \mathrm { kJ } {/tex}
On the basis of Le Chatelier's principle, the condition favourable for the forward reaction is

A

increasing temperature as well as pressure

lowering the temperature and increasing the pressure

C

any value of temperature and pressure

D

lowering of temperature as well as pressure

Explanation

Q 10.    

Correct4

Incorrect-1

When rain is accompanied by a thunderstorm, the collected rain water will have a pH value

A

slightly higher than that when the thunderstorm is not there

B

uninfluenced by occurrence of thunderstorm

C

which depends on the amount of dust in air

slightly lower than that of rain water without thunderstorm.

Explanation

Q 11.    

Correct4

Incorrect-1

The conjugate base of {tex} \mathrm { H } _ { 2 } \mathrm { PO } _ { 4 } ^ { - } {/tex} is

A

{tex} \mathrm { H } _ { 3 } \mathrm { PO } _ { 4 } {/tex}

B

{tex} \mathrm { P } _ { 2 } \mathrm { O } _ { 5 } {/tex}

C

{tex} \mathrm { PO } _ { 4 } ^ { 3 - } {/tex}

{tex} \mathrm { HPO } _ { 4 } ^ { 2 - } {/tex}

Explanation

Q 12.    

Correct4

Incorrect-1

What is the equilibrium expression for the reaction
{tex} \mathrm { P } _ { 4 } ( s ) + 5 \mathrm { O } _ { 2 } ( \mathrm { g } ) \rightleftharpoons \mathrm { P } _ { 4 } \mathrm { O } _ { 10 } ( \mathrm { s } ) ? {/tex}

A

{tex} K _ { \mathrm { c } } = \left[ \mathrm { O } _ { 2 } \right] ^ { 5 } {/tex}

B

{tex} K _ { \mathrm { c } } = \left[ \mathrm { P } _ { 4 } \mathrm { O } _ { 10 } \right] / 5 \left[ \mathrm { P } _ { 4 } \right] \left[ \mathrm { O } _ { 2 } \right] {/tex}

C

{tex} K _ { \mathrm { c } } = \left[ \mathrm { P } _ { 4 } \mathrm { O } _ { 10 } \right] / \left[ \mathrm { P } _ { 4 } \right] \left[ \mathrm { O } _ { 2 } \right] ^ { 5 } {/tex}

{tex} K _ { \mathrm { c } } = 1 / \left[ \mathrm { O } _ { 2 } \right] ^ { 5 } {/tex}

Explanation

Q 13.    

Correct4

Incorrect-1

For the reaction, {tex} \mathrm { CO } ( \mathrm { g } ) + \mathrm { Cl } _ { 2 } ( \mathrm { g } ) \rightleftharpoons \mathrm { COCl } _ { 2 } ( \mathrm { g } ) {/tex} the {tex} K _ { p } / K _ { c } {/tex} is equal to

A

{tex} \sqrt { R T } {/tex}

B

{tex} R T {/tex}

{tex}1 / R T {/tex}

D

{tex}1.0{/tex}

Explanation

Q 14.    

Correct4

Incorrect-1

The equilibrium constant for the reaction
{tex} \mathrm { N } _ { 2 } ( \mathrm { g } ) + \mathrm { O } _ { 2 } ( \mathrm { g } ) \rightleftharpoons 2 \mathrm { NO } _ { 2 } ( \mathrm { g } ) {/tex} at temperature {tex} \mathrm { T } {/tex} is {tex} 4 \times 10 ^ { - 4 } {/tex}
The value of {tex} K _ { c } {/tex} for the reaction
{tex} \mathrm { NO } _ { 2 } ( \mathrm { g } ) \rightleftharpoons \frac { 1 } { 2 } \mathrm { N } _ { 2 } ( \mathrm { g } ) + \frac { 1 } { 2 } \mathrm { O } _ { 2 } ( \mathrm { g } ) {/tex} at the same temperature

A

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

{tex}50{/tex}

C

{tex} 2.5 \times 10 ^ { 2 } {/tex}

D

{tex}0.02{/tex}

Explanation

Q 15.    

Correct4

Incorrect-1

{tex} \left. \text { The molar solubility (in mol } \mathrm { L } ^ { - 1 } \right) {/tex} of a sparingly soluble salt {tex} \mathrm { MX } _ { 4 } {/tex} is 's' . The corresponding solubility product is {tex} K _ { s p } . \mathrm { 's } ^ { \prime } {/tex} is given in term of {tex} K _ { s p } {/tex} by the relation:

A

{tex} s = \left( 256 K _ { s p } \right) ^ { 1 / 5 } {/tex}

B

{tex} s = \left( 128 K _ { s p } \right) ^ { 1 / 4 } {/tex}

C

{tex} s = \left( K _ { s p } / 128 \right) ^ { 1 / 4 } {/tex}

{tex} \mathrm { s } = \left( K _ { s p } / 256 \right) ^ { 1 / 5 } {/tex}

Explanation

Q 16.    

Correct4

Incorrect-1

If {tex} \alpha {/tex} is the degree of dissociation of {tex} \mathrm { Na } _ { 2 } \mathrm { SO } _ { 4 } {/tex} , the Vant Hoff's factor (i) used for calculating the molecular mass is

A

{tex} 1 - 2 \alpha {/tex}

{tex} 1 + 2 \alpha {/tex}

C

{tex} 1 - \alpha {/tex}

D

{tex} 1 + \alpha {/tex}

Explanation

Q 17.    

Correct4

Incorrect-1

The solubility product of a salt having general formula {tex} \mathrm { MX } _ { 2 } , {/tex} in water is : {tex} 4 \times 10 ^ { - 12 } {/tex} . The concentration of {tex} \mathrm { M } ^ { 2 + } {/tex} ions in the aqueous solution of the salt is

A

{tex} 4.0 \times 10 ^ { - 10 } \mathrm { M } {/tex}

B

{tex} 1.6 \times 10 ^ { - 4 } \mathrm { M } {/tex}

{tex} 1.0 \times 10 ^ { - 4 } \mathrm { M } {/tex}

D

{tex} 2.0 \times 10 ^ { - 6 } \mathrm { M } {/tex}

Explanation

Q 18.    

Correct4

Incorrect-1

The exothermic formation of {tex} \mathrm { CIF } _ { 3 } {/tex} is represented by the equation:
{tex} \mathrm { Cl } _ { 2 } ( \mathrm { g } ) + 3 \mathrm { F } _ { 2 } ( \mathrm { g } ) \rightleftharpoons 2 \mathrm { ClF } _ { 3 } ( \mathrm { g } ) ; \Delta \mathrm { H } = - 329 \mathrm { kJ } {/tex}
Which of the following will increase the quantity of {tex} \mathrm { CIF } _ { 3 } {/tex} in an equilibrium mixture of {tex} \mathrm { Cl } _ { 2 } , \mathrm { F } _ { 2 } {/tex} and {tex} \mathrm { ClF } _ { 3 } ? \quad [ 2005 \mathrm { I } ] {/tex}

Adding {tex} \mathrm { F } _ { 2 } {/tex}

B

Increasing the volume of the container

C

Removing {tex} \mathrm { Cl } _ { 2 } {/tex}

D

Increasing the temperature

Explanation

Q 19.    

Correct4

Incorrect-1

For the reaction {tex} : 2 \mathrm { NO } _ { 2 ( \mathrm { g } ) } \rightleftharpoons 2 \mathrm { NO } _ { ( \mathrm { g } ) } + \mathrm { O } _ { 2 ( \mathrm { g } ) } {/tex}, {tex} \left( \mathrm { K } _ { \mathrm { c } } = 1.8 \times 10 ^ { - 6 } \text { at } 184 ^ { \circ } \mathrm { C } \right) ( \mathrm { R } = 0.0831 \mathrm { kJ } / ( \mathrm { mol } . \mathrm { K } ) ) {/tex}
When {tex} \mathrm { K } _ { \mathrm { p } } {/tex} and {tex} \mathrm { K } _ { \mathrm { c } } {/tex} are compared at {tex} 184 ^ { \circ } \mathrm { C } , {/tex} it is found that

A

Whether {tex} K _ { p } {/tex} is greater than, less than or equal to {tex} K _ { c } {/tex} depends upon the total gas pressure

B

{tex} K _ { p } = K _ { c } {/tex}

C

{tex} K _ { p } {/tex} is less than {tex} K _ { c } {/tex}

{tex} K _ { p } {/tex} is greater than {tex} K _ { c } {/tex}

Explanation

Q 20.    

Correct4

Incorrect-1

Hydrogen ion concentration in {tex} \mathrm { mol } / \mathrm { L } {/tex} in a solution of {tex} \mathrm { pH } = 5.4 {/tex} will be :

{tex} 3.98 \times 10 ^ { - 6 } {/tex}

B

{tex} 3.68 \times 10 ^ { - 6 } {/tex}

C

{tex} 3.88 \times 10 ^ { 6 } {/tex}

D

{tex} 3.98 \times 10 ^ { 8 } {/tex}

Explanation

Q 21.    

Correct4

Incorrect-1

What is the conjugate base of {tex} \mathrm { OH } ^ { - } ? {/tex}

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

B

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

C

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

D

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

Explanation

Q 22.    

Correct4

Incorrect-1

An amount of solid {tex} \mathrm { NH } _ { 4 } \mathrm { HS } {/tex} is placed in a flask already containing ammonia gas at a certain temperature and 0.50 atm pressure. Ammonium hydrogen sulphide decomposes to yield {tex} \mathrm { NH } _ { 3 } {/tex} and {tex} \mathrm { H } _ { 2 } \mathrm { S } {/tex} gases in the flask. When the decomposition reaction reaches equilibrium, the total pressure in the flask rises to 0.84 atm? The equilibrium constant for {tex} \mathrm { NH } _ { 4 } \mathrm {HS } {/tex} decomposition at this temperature is

0.11

B

0.17

C

0.18

D

0.30

Explanation



Q 23.    

Correct4

Incorrect-1

Phosphorus pentachloride dissociates as follows, in a closed reaction vessel \[ \mathrm { PCl } _ { 5 } ( \mathrm { g } ) \rightleftharpoons \mathrm { PCl } _ { 3 } ( \mathrm { g } ) + \mathrm { Cl } _ { 2 } ( \mathrm { g } ) \]
If total pressure at equilibrium of the reaction mixture is {tex} \mathrm { P } {/tex} and degree of dissociation of {tex} \mathrm { PCl } _ { 5 } {/tex} is {tex} \mathrm { x } {/tex} , the partial pressure of {tex} \mathrm { PCl } _ { 3 } {/tex} will be

A

{tex} \left( \frac { x } { x - 1 } \right) P {/tex}

B

{tex} \left( \frac { x } { 1 - x } \right) P {/tex}

{tex} \left( \frac { x } { x + 1 } \right) \mathrm { P } {/tex}

D

{tex} \left( \frac { 2 x } { 1 - x } \right) { \mathrm { P } } {/tex}

Explanation

Q 24.    

Correct4

Incorrect-1

The equilibrium constant for the reaction \[ \mathrm { SO } _ { 3 } ( \mathrm { g } ) \rightleftharpoons \mathrm { SO } _ { 2 } ( \mathrm { g } ) + \frac { 1 } { 2 } \mathrm { O } _ { 2 } ( \mathrm { g } ) \]
is {tex} K _ { \mathrm { c } } = 4.9 \times 10 ^ { - 2 } {/tex} . The value of {tex} K _ { \mathrm { c } } {/tex} for the reaction \[ \begin{array} { l } { 2 \mathrm { SO } _ { 2 } ( \mathrm { g } ) + \mathrm { O } _ { 2 } ( \mathrm { g } ) \rightleftharpoons 2 \mathrm { SO } _ { 3 } ( \mathrm { g } ) } \end{array} \]
will be

A

{tex} 9.8 \times 10 ^ { - 2 } {/tex}

B

{tex} 4.9 \times 10 ^ { - 2 } {/tex}

416

D

{tex} 2.40 \times 10 ^ { - 3 } {/tex}

Explanation

Q 25.    

Correct4

Incorrect-1

Given the data at {tex} 25 ^ { \circ } \mathrm { C } {/tex} \[ \begin{array} { l l } { \mathrm { Ag } + \mathrm { I } ^ { - } \longrightarrow \mathrm { Agl } + \mathrm { e } ^ { - } } & { \mathrm { E } ^ { \circ } = 0.152 \mathrm { V } } \\ { \mathrm { Ag } \longrightarrow \mathrm { Ag } ^ { + } + \mathrm { e } ^ { - } } & { \mathrm { E } ^ { \circ } = - 0.800 \mathrm { V } } \end{array} \]
What is the value of {tex} \log K _ { \mathrm { sp } } {/tex} for {tex} \mathrm { Agl } ? ( 2.303 \mathrm { RT } / \mathrm { F } = 0.059 \mathrm { V } ) {/tex}

A

{tex} - 37.83 {/tex}

{tex} - 16.13 {/tex}

C

{tex} - 8.12 {/tex}

D

{tex} + 8.612 {/tex}

Explanation