The Ka value of nitrous acid, HNO2 , is 4.0 × 10¯4 . What is the equilibrium constant for the reaction; NO2¯ + H2O <-> HNO2 + OH¯ ?

Answer 1

The equation you have written is just the hydrolysis of the NO2^- so you want Kb which is Kw/Ka.

Answer 2

Thomas, check your 2-16-11,4:29pm post.