At a particular temperature and atmospheric pressure, the solid and liquid
phases of a pure substance can exist in equilibrium. Choose the terms
which define this temperature.

(a) Normal melting point

(b) Equilibrium temperature

(c) Boiling point

(d) Freezing point

1. (a, b)

2. (b, c)

3. (c, d)

4. (a, d)

For the reaction N₂O₄(g) ⇌ 2NO₂(g), the value of K(equilibrium constant) is 50 at 400 K and 1700 at 500 K. Which of the following option(s) is/are correct?

1. (a, b, d)

2. (b, c, d)

3. (b, d, a)

4. (a, c, d)

The addition of a small amount of argon at a constant volume will not affect the equilibrium of the following reaction:

At 500 K, equilibrium constant, K_c, for the following reaction is 5.

$\frac{1}{2}{\mathrm{H}}_2\left(\mathrm{g}\right)+\frac{1}{2}{\mathrm{I}}_2\left(\mathrm{g}\right)\rightleftharpoons \mathrm{HI}\left(\mathrm{g}\right)$

What would be the equilibrium constant K_c for the reaction?

$2\mathrm{HI}\left(\mathrm{g}\right)\rightleftharpoons {\mathrm{H}}_2\left(\mathrm{g}\right)+{\mathrm{I}}_2\left(\mathrm{g}\right)$

1.  0.04

2.  0.4

3.  25

4.  2.5

On increasing the pressure, the direction in which the gas phase reaction proceeds to re-establish equilibrium is predicted by applying Le-Chatelier's principle. Consider the reaction,

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

Which of the following is correct, if the total pressure at which the equilibrium is established is increased without changing the temperature?

Which of the following alternatives best describes the reaction A ⇌ B at its halfway point?

${\mathrm{K}}_{\mathrm{a}}$ for ${\mathrm{CH}}_3\mathrm{COOH}$ is $1.8\times {10}^{-5}$ and K_b for ${\mathrm{NH}}_4\mathrm{OH}$ is $1.8\times {10}^{-5}$. The pH of ammonium acetate will be: 

1. 7.005

2. 4.75

3. 7.0

4. Between 6 and 7

The value of the pH of \(0.01 \) \(\text{mol dm}^{-3}   \)\(\text{CH}_3\text{COOH}\) \(\left(K_a=1.74 \times 10^{-5}\right)\)  is:

Among the following solvents, silver chloride is most soluble in:

1. $0.1 \mathrm{mol} {\mathrm{dm}}^{-3} {\mathrm{AgNO}}_3$ solution

2. $0.1 \mathrm{mol} {\mathrm{dm}}^{-3} \mathrm{HCl}$ solution

3. ${\mathrm{H}}_2\mathrm{O}$

4. Aqueous ammonia

The mixture that will produce a buffer solution when mixed in equal volumes is: