The dissociation constants for acetic acid and HCN at 25 °C are 1.5 x 10^-5 and 4.5 x 10^-10, respectively. The equilibrium constant for the equilibrium, 
CN^- + CH₃COOH  ⇌  HCN + CH₃COO^- 
would be:
1. $3.0\times {10}^5$
2. $3.0\times {10}^{-5}$
3. $3.0\times {10}^{-4}$
4. $3.0\times {10}^4$

Equal volumes of three acid solutions of pH 3, 4 and 5 are mixed in a vessel. What will be the H⁺ ion concentration in the mixture?
1. $1.11\times {10}^{-4}$ $\mathrm{M}$
2. $3.7\times {10}^{-4}$ $\mathrm{M}$
3. $3.7\times {10}^{-3}$ $\mathrm{M}$
4. $1.11\times {10}^{-3}$ $\mathrm{M}$

If the concentration of OH ' ions in the reaction 

The dissociation equilibrium of a gas AB₂ can be represented as 
 $2A{B}_2\left(g\right)$ $\leftrightharpoons$ $2AB\left(g\right)$ $+$ $B_2\left(g\right)$ $$
The degree of dissociation is ‘x’ and is small compared to 1. The expression relating the degree of dissociation (x) with equilibrium constant K_P and total pressure p is:
1. (2KP/p)
2. (2Kp /p)^1/3
3. (2KP/p)^1/2
4. (KP/P)

The value of K_P1 and K_p2 for the reactions
 $X$ $\leftrightharpoons$ $Y$ $+Z$ $......\left(i\right)$
$and$ $A$ $\leftrightharpoons 2B$ $......\left(ii\right)\hspace{0.17em}$
are in the ratio of 9 : 1. If the degree of dissociation of X and A is equal, then the total pressure at equilibrium(i) and (ii) are in the ratio:

The value of the equilibrium constant of the reaction 
 \(HI \left(\right. g \left.\right)\) \(\leftrightharpoons\) \(\frac{1}{2} H_{2} \left(\right. g \left.\right)\) \(+\) \(\frac{1}{2} I_{2}\) is 8.0.
The equilibrium constant of the reaction
 \(H_{2} \left(\right. g \left.\right)\) \(+\) \(I_{2} \left(\right. g \left.\right)\) \(\leftrightharpoons\) \(2 HI \left(\right. g \left.\right)\) will be-

The pOH of a solution at 25 °C that contains 1×10^-10 M of hydronium ions is:

A weak acid, HA, has a K_a of 1.00×10^-5. If 0.100 mole of this acid is dissolved in one litre of water, the percentage of acid dissociated at equilibrium is closest to:

1. 99.0%

2. 1%

3. 99.9%

4. 0.100%

The following equilibrium constants are given: 
N₂ + 3H₂ ⇌ 2NH₃; K₁ 
N₂ + O₂ ⇌ 2NO; K₂ 
H₂ + 1/2O₂ ⇌ H₂O; K₃ 

The equilibrium constant for the oxidation of NH₃ by oxygen to give NO is:

1. $K_2{K}_3^3/K_1$

2. $K_2{K}_3^2/K_1$

3. $K_2^2{K}_3/K_1$

4. $K_1{K}_2/K_3$