Question

Will the following salt, NaNO2, dissolve in water to make an acidic, basic or neutral solution? (HNO2 Ka = 4.0 x 10-4)

Answer 1

It will make a slightly basic solution since NO2^- will hydrolyze with water; i.e.,

NO2^- + HOH --> HNO2 + OH^-
HNO2 being a weak acid and OH^- being a strong base makes it slightly basic.