Question

Find the Ka of nitrous acid given that a 0.20 M solution of the acid has a hydrogen ion concentration of 2.8*10-3 M. HNO2 (aq) ? H+ (aq) + NO2- (aq)

Answer 1

3.92 x 10⁻⁵.

Step-by-step explanation:

∵ [H⁺] = √(Ka.c)

∴ Ka = [H⁺]²/c = (2.8 x 10⁻³)²/(0.20) = 3.92 x 10⁻⁵.