Chemistry NCERT Exemplar Solutions Class 11th Chapter Seven

Which of the following options will be correct for the stage of half completion of the reaction A ⇌ B.

(i) ∆Gᶱ = 0

(ii) ∆Gᶱ> 0

(iii) ∆Gᶱ< 0

(iv) ∆Gᶱ= –RT ln2

Ka for CH₃COOH is 1.8 * 10^–5 and K b for NH₄OH is 1.8 * 10^–5 . The pH of ammonium acetate will be

(i) 7.005

(ii) 4.75

(iii) 7.0

(iv) Between 6 and 7

What will be the value of pH of 0.01 mol dm^–3 CH₃COOH (Ka = 1.74 * 10^–5 )?

(i) 3.4

(ii) 3.6

(iii) 3.9

(iv) 3.0

In which of the following solvents is silver chloride most soluble?

(i) 0.1 mol dm^–3 AgNO3 solution

(ii) 0.1 mol dm^–3 HCl solution

(iii) H₂O

(iv) Aqueous ammonia

Which of the following will produce a buffer solution when mixed in equal volumes?

(i) 0.1 mol dm^–3 NH₄OH and 0.1 mol dm^–3 HCl

(ii) 0.05 mol dm^–3 NH₄OH and 0.1 mol dm^–3 HCl

(iii) 0.1 mol dm^–3 NH₄OH and 0.05 mol dm^–3 HCl

(iv) 0.1 mol dm^–3 CH₄COONa and 0.1 mol dm^–3 NaOH

Acidity of BF₃ can be explained on the basis of which of the following concepts?

(i) Arrhenius concept

(ii) Bronsted Lowry concept

(iii) Lewis concept

(iv) Bronsted Lowry as well as Lewis concept

Acidity of BF₃ can be explained on the basis of which of the following concepts?

(i) Arrhenius concept

(ii) Bronsted Lowry concept

(iii) Lewis concept

(iv) Bronsted Lowry as well as Lewis concept

K_a1 , K_a2 and K_a3 are the respective ionisation constants for the following reactions.

H₂S $\mathit{}\to$   H⁺ + HS

HS^–  $\mathit{}\to$ H⁺ + S²

 H₂S $\mathit{}\to$ 2H⁺ + S²

The correct relationship between is K_a1 , K_a2 and K_a3

1. K_a3= K_a1 * K_a2
2. K_a3= K_a1 + K_a2
3. K_a3= K_a1 – K_a2
4. K_a3= K_a1 / K_a2

The ionisation constant of an acid, Ka , is the measure of strength of an acid. The Ka values of acetic acid, hypochlorous acid and formic acid are 1.74 * 10^–5, 3.0 * 10^–8 and 1.8 * 10^–4 respectively. Which of the following orders of pH of 0.1 mol dm^–3 solutions of these acids is correct?

(i) Acetic acid > hypochlorous acid > formic acid

(ii) Hypochlorous acid > acetic acid > formic acid

(iii) Formic acid > hypochlorous acid > acetic acid

(iv) Formic acid > acetic acid > hypochlorous acid

The pH of neutral water at 25°C is 7.0. As the temperature increases, ionisation of water increases, however, the concentration of H⁺ ions and OH^– ions are equal. What will be the pH of pure water at 60°C?

(i) Equal to 7.0

(ii) Greater than 7.0

(iii) Less than 7.0

(iv) Equal to zero