For the equilibrium that exists in an aqueous solution of nitrous acid (HNO₂,a weak acid),the equilibrium-constant expression is

Question

Quizplus · Accepted Answer

The equilibrium-constant expression for the dissociation of HNO2 is:
HNO2 ⇌ H+ + NO2−
The expression is given by:
K = [H+][NO2−]/[HNO2]
Therefore, the correct equilibrium-constant expression is:
K = [H+][NO2−]/[HNO2] = [HSO−][NO2−]/[HNO2] = [HSO−][NO2−]/([HSO−] + [SO2−]) = 4.5 × 10-4

For the Equilibrium That Exists in an Aqueous Solution of Nitrous