For the reaction

N₂ (g) + O₂ (g) $\rightleftharpoons$ 2NO (g), the value of K_c at 800°C is 0.1. When the equilibrium concentration of both the reactants is 0.5 mol, what is the value of K_p at the same temperature?

• 0.5

• 0.1

• 0.01

• 0.025

642.

The species among the following, which can act as an acid and a base is

• HSO${}_4^{-}$

• SO${}_4^{2-}$

• H₃O⁺

• Cl^-

A buffer solution has equal volumes of 0.2 M NH₄OH and 0.02 M NH₄Cl. The pK_b of the base is 5. The pH is

• 10

• 9

• 4

• 7

A precipitate of AgCl is formed when equal volumes of the following are mixed [K_sp for AgCl = 10^-10]

• 10^-4 M AgNO₃ and 10^-7 M HCl

• 10^-5 M AgNO₃ and 10^-6 M HCl

• 10^-5 M AgNO₃ and 10^-4 M HCl

• 10^-6 M AgNO₃ and 10^-6 M HCl

4 moles each of SO₂ and O₂ gases are allowed to react to form SO₃, in a closed vessel. At equilibrium 25% of O₂ is used up. The total number of moles of all the gases at equilibrium is :

• 6.5

• 7.0

• 8.0

• 2.0

Solubility product of a salt AB is 1 x 10^-8 M² in a solution in which the concentration of A⁺ ions is 10M.The salt will precipitate when the concentration of B ions is kept :

• between 10^-8 M to 10^-7 M

• between 10^-7 M to 10^-8 M

• >10^-5 M

• <10^-8 M

The pH of 10^-8 M HCl solution is:

• 8

• more than 8

• between 6 and 7

• slightly more than 7

Hydroxyl ion concentration of 10^-2 M HCl is

• 1 × 10¹ mol dm^-3

• 1 × 10^-12 mol dm^-3

• 1 × 10^-1 mol dm^-3

• 1 × 10^-14 mol dm^-3

A ligand can also be regarded as

• Lewis acid

• Bronsted base

• Lewis base

• Bronsted acid

Which one of the following salts on being dissolved in water gives pH > 7 at 25°C?

• KCN

• KNO₃

• NH₄Cl

• NH₄CN