Consider the following reversible reactions,

N₂(g) + 3H₂(g) $\rightleftharpoons$ 2NH₃(g) (K₁)  ...(i)

N₂ (g) + O₂(g) $\rightleftharpoons$2NO (g) (K₂) ....(ii)

H₂ (g) + $\frac{1}{2}{\mathrm{O}}_2\left(\mathrm{g}\right) \rightleftharpoons {\mathrm{H}}_2\mathrm{O} \left(\mathrm{g}\right) \left({\mathrm{K}}_3\right) ....\left(\mathrm{iii}\right)$

The equilibrium constant for the reaction:

2NH₃(g) + $\frac{5}{2}{\mathrm{O}}_2\left(\mathrm{g}\right)\hspace{0.17em}\rightleftharpoons 2\mathrm{NO}\left(\mathrm{g}\right) + 3{\mathrm{H}}_2\mathrm{O} \left(\mathrm{g}\right)$ will be

• K₁ K₂ K₃

• $\frac{{\mathrm{K}}_1{\mathrm{K}}_2}{{\mathrm{K}}_3}$

• $\frac{{\mathrm{K}}_1{\mathrm{K}}_3^3}{{\mathrm{K}}_2}$

• $\frac{{\mathrm{K}}_2{\mathrm{K}}_3^3}{{\mathrm{K}}_1}$

The number of moles of sodium acetate to be added to 0.1 M acetic acid for the buffer to have a pH = 4.7 is [pK_a for acetic acid is 4.7]

• 0.2

• 0.4

• 0.1M

• None of these

If K_c is the equilibrium constant for the formation of NH₃, the dissociation constant of NH₃ under the same condition will be

• $\frac{1}{{\mathrm{K}}_{\mathrm{c}}}$

• ${\mathrm{K}}_{\mathrm{C}}^2$

• $\sqrt{{\mathrm{K}}_{\mathrm{C}}}$

• K_C

The pH of a soft drink is 3.92. The hydrogen ion concentration will be

( given antilog 0.08 = 1.2)

• 1.96 × 10^-2 mol L^-1

• 1.96 × 10^-3 mol L^-1

• 1.2 × 10^-4 mol L^-1

• 1.2 × 10^-3 mol L^-1

285.

An example of a salt that will not hydrolyse is

• CH₃COONH₄

• CH₃COOK

• NH₄Cl

• KCl

20 mL of 0.25 N strong acid and 30 mL 0·2 N of strong base are mixed; the resulting solution is

• 0.02 N acidic

• 0.025 N basic

• 0.02 N basic

• 0.025 N acidic

The rate of forward reaction is two times that of reverse reaction at a given temperature and identical concentration. K

• 2.5

• 2.0

• 0.5

• 1.5

Ammonium ion is

• neither an acid nor base

• both an acid and a base

• a conjugate acid

• a conjugate base

A is an aqueous acid; B is an aqueous base. They are diluted separately, then

• pH of A decreases and pH of B increases

• pH of A increases and pH of B decreases till pH in each case is 7

• pH of A and B increase

• pH of B and A decrease

What is the solubility of silver bromide in one litre of 0.4 molar NH₃ solution (K =10x10⁸)?

• 80 × 10^-6 mol

• 2.8 × 10^-3 mol

• 115 × 10^-3 mol

• 0.98 g