Which of the following alternatives best describes the reaction A ⇌ B at its halfway point?
1. \(\Delta G^{\ominus}=0\)
2. \(\Delta G^{\ominus}>0\)
3. \(\Delta G^{\ominus}<0\)
4. \(\Delta G^{\ominus}=-RTlnK\)

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?

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

${\mathrm{K}}_{\mathrm{a}}$ 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:

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:

Acidity of BF₃ can be explained on the basis of: 

1. Arrhenius concept

2. Bronsted Lowry concept 

3. Lewis concept

4. Bronsted Lowry as well as Lewis concept

${\mathrm{K}}_{{\mathrm{a}}_1},$ ${\mathrm{K}}_{{\mathrm{a}}_2}$ $\mathrm{and}$ ${\mathrm{K}}_{{\mathrm{a}}_3}$ are the respective ionisation constants for the following reactions.
\(\mathrm{H}_2 \mathrm{~S} \rightleftharpoons \mathrm{H}^{+}+\mathrm{HS}^{-}\)
\(\mathrm{HS}^{-} \rightleftharpoons \mathrm{H}^{+}+\mathrm{S}^{2-}\)
\(\mathrm{H}_2 \mathrm{~S} \rightleftharpoons 2 \mathrm{H}^{+}+\mathrm{S}^{2-}\)
The correct relationship between ${\mathrm{K}}_{{\mathrm{a}}_1},$ ${\mathrm{K}}_{{\mathrm{a}}_2}$ $\mathrm{and}$ ${\mathrm{K}}_{{\mathrm{a}}_3}$ is:
1. \(\mathrm{K}_{\mathrm{a}_3}=\mathrm{K}_{\mathrm{a}_1} \times \mathrm{K}_{\mathrm{a}_2} \)
2. \(\mathrm{K}_{\mathrm{a}_3}=\mathrm{K}_{\mathrm{a}_1}+\mathrm{K}_{\mathrm{a}_2} \)
3. \(K_{a_3}=K_{a_1}-K_{a_2} \)
4. \(\mathrm{K}_{\mathrm{a}_3}=\mathrm{K}_{\mathrm{a}_1} / \mathrm{K}_{\mathrm{a}_2}\)