What is the pH of 0.01 M glycine solution? For glycine, Ka₁ = 4.5 ˣ 10⁻³ and Ka₂ =1.7 ˣ 10⁻¹⁰ at 298 K

Options

(a) 3
(b) 10
(c) 6.1
(d) 7.2

Correct Answer:

6.1

Explanation:

K = Kₐ₁ x Kₐ₂ = 4.5 x 10⁻³ * 1.7 x 10⁻¹⁰,
7.65 x 10⁻¹³,
[H⁺] = √KC = √7.65 x 10⁻¹³ x 0.01 ,
= √7.65 x 10⁻¹⁵
= 0.87 x 10⁻⁷. pH = -log 0.87 x 10⁻⁷
= 7 – 0.93 = 6.07.