Q 21 :

The number of correct statement/s involving equilibria in physical processes from the following is ________           [2023]

(A) Equilibrium is possible only in a closed system at a given temperature.

(B) Both the opposing processes occur at the same rate.

(C) When equilibrium is attained at a given temperature, the value of all its parameters become equal.

(D) For dissolution of solids in liquids, the solubility is constant at a given temperature.

Q 22 :

$\mathrm{A}\left(\mathrm{g}\right)\rightleftharpoons 2\mathrm{B}\left(\mathrm{g}\right)+\mathrm{C}\left(\mathrm{g}\right)$

For the given reaction, if the initial pressure is 450 mm Hg and the pressure at time t is 720 mm Hg at a constant temperature T and constant volume V. The fraction of A(g) decomposed under these conditions is $x\times {10}^{-1}$. The value of $x$ is ______ (Nearest Integer)            [2023]

Q 23 :

A mixture of 1 mole of ${\mathrm{H}}_2\mathrm{O}$ and 1 mole of CO is taken in a 10 litre container and heated to 725 K. At equilibrium 40% of water by mass reacts with carbon monoxide according to the equation:

$\mathrm{CO}\left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)\rightleftharpoons {\mathrm{CO}}_2\left(\mathrm{g}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)$

The equilibrium constant ${\mathrm{K}}_{\mathrm{c}}\times {10}^2$ for the reaction is ________. (Nearest integer)         [2023]

Q 24 :

4.5 moles each of hydrogen and iodine is heated in a sealed ten litre vessel. At equilibrium, 3 moles of HI were found. The equilibrium constant for ${\mathrm{H}}_2\left(\mathrm{g}\right)+{\mathrm{I}}_2\left(\mathrm{g}\right)\rightleftharpoons 2\mathrm{HI}\left(\mathrm{g}\right)$ is ________.           [2023]

Q 25 :

Consider the general reaction given below at 400 K

             $xA\left(g\right)\rightleftharpoons yB\left(g\right)$

The values of $K_p$ and $K_c$ are studied under the same condition of temperature but variation in $x$ and $y$.

(i) $K_p=85.87$ and $K_c=2.586$ (appropriate units)
(ii) $K_p=0.862$ and $K_c=28.62$ (appropriate units)

The values of $x$ and $y$ in (i) and (ii) respectively are:                      [2026]

• (i) 1, 2  (ii) 2, 1

   

• (i) 4, 1  (ii) 4, 1

   

• (i) 3, 1  (ii) 3, 1

   

• (i) 1, 3  (ii) 2, 1

   

Q 26 :

For the following gas phase equilibrium reaction at constant temperature,

${\mathrm{NH}}_3\left(\mathrm{g}\right)\rightleftharpoons \frac{1}{2}{\mathrm{N}}_2\left(\mathrm{g}\right)+\frac{3}{2}{\mathrm{H}}_2\left(\mathrm{g}\right)$

if the total pressure is $\sqrt{3}$ atm and the pressure equilibrium constant $\left(K_p\right)$ is 9 atm, then the degree of dissociation is given as ${(x\times {10}^{-2})}^{-1/2}.$ The value of $x$ is ______.(nearest integer)                       [2026]

Q 27 :

Consider the following gaseous equilibrium in a closed container of volume 'V' at T(K).

${\mathrm{P}}_2\left(\mathrm{g}\right)+{\mathrm{Q}}_2\left(\mathrm{g}\right)\rightleftharpoons 2\mathrm{PQ}\left(\mathrm{g}\right)$

2 moles each of ${\mathrm{P}}_2\left(\mathrm{g}\right)$, ${\mathrm{Q}}_2\left(\mathrm{g}\right)$ and $\mathrm{PQ}\left(\mathrm{g}\right)$ are present at equilibrium. Now one mole each of $\text{'}{\mathrm{P}}_2\text{'}$ and $\text{'}{\mathrm{Q}}_2\text{'}$ are added to the equilibrium keeping the temperature at T(K). The number of moles of ${\mathrm{P}}_2$, ${\mathrm{Q}}_2$ and $\mathrm{PQ}$ at the new equilibrium, respectively, are                  [2026]

• 2.67, 2.67, 2.67

   

• 1.21, 2.24, 1.56

   

• 1.66, 1.66, 1.66

   

• 2.56, 1.62, 2.24