11.

p_Ka of a weak acid (H_A) and pKb of a weak base (BOH) are 3.2 and 3.4, respectively. The p_H of their salt (AB) solution is

• 7.2

• 6.9

• 7.0

• 7.0

In the following reactions, ZnO is respectively acting as a/an :
(a) ZnO + Na₂O → Na₂ZnO₂
(b) ZnO + CO₂ → ZnCO₃

• base and acid

• base and base

• acid and acid

• acid and acid

The equilibrium constants K_P1 and K_P2 for the reactions X ⇌2Y and Z ⇌ P + Q, respectively are in the ratio of 1 : 9. If the degree of dissociation of X and Z be equal then the ratio of total pressure at these equilibria is

• 1:1

• 1:36

• 1:9

• 1:9

For the following three reactions a, b and c, equilibrium constants are given

a. CO (g) + H₂O (g) ⇌ CO₂ (g)+ H₂ (g); K₁
b. CH₄(g) + H₂O (g) ⇌ CO (g) + 3H₂ (g); K₂
c. CH₄(g) + 2H₂O (g) ⇌ CO₂ (g) + 4H₂ (g); K₂
Which of the following relations is correct?

• K₁√K₂ = K₃

• K₂K₃ = K₁

• K₃ = K₁K₂

• K₃ = K₁K₂

Four species are listed below
i. HCO3⁻
ii. H₃O⁺
iii. HSO₄⁻
iv. HSO₃F
Which one of the following is the correct sequence of their acid strength?

•  iv < ii < iii < i

• ii < iii < i < iv

• i < iii < ii < iv

• i < iii < ii < iv

The p_Ka of a weak acid, H_A, is 4.80. The p_Kb of a weak base, BOH, is 4.78. The pH of an aqueous solution of the corresponding salt, BA, will be 

• 9.58

• 4.79

• 7.01

• 7.01

The pKa of a weak acid (HA) is 4.5. The pOH of an aqueous buffered solution of H_A in which 50% of the acid is ionized is

• 4.5

• 2.5 

• 9.5

• 9.5

Regular use of which of the following fertilizers increases the acidity of soil ?

• Potassium nitrate

• Urea

• Superphosphate of lime

• Superphosphate of lime

An ideal gas is allowed to expand both reversibly and irreversibly in an isolated system. If Ti is the initial temperature and Tf is the final temperature, which of the following statements is correct?

• (T_f)_irrev > (T_f)_rev

• T_f > T_i for reversible process but Tf = Ti for irreversible process

• (T_f)_rev = (T_f)_irrev

• (T_f)_rev = (T_f)_irrev

The equilibrium constant for the reaction


is K_c = 4.9 × 10^–2. The value of K_c for the reaction'
2SO₂ (g) +O₂(g) ⇌ 2SO₃ (g) will be

• 416

• 2.40 × 10^–3

• 9.8 × 10^–2

• 9.8 × 10^–2