Question

What is [NH₄⁺] in a solution that is 0.02 M NH₃ and 0.01 M KOH? [K_b(NH₃) = 1.8 x 10^–5]

(a) 3.6 x 10^–5 M 

(b) 1.8 x 10^–5 M

(c) 0.9 x 10^–5 M 

(d) 7.2 x 10^–5 M

Answer 1

Correct option: (a) 3.6 x 10^-5

Explanation: 

NH₄OH ⇌ NH₄⁺ + OH^-,