Answer to Question #303797 in Physical Chemistry for Chemistry

Question

Describe the effect on the pH that results by adding

a. NaNO2 to HNO2

b. NaNO3 to HNO3

Answer 1

HNO3 is a strong acid, it dissociates completely, thus additional portion of NO3 ions wouldn't change the pH much. In contrary HNO2 is a weak acid...it doesn't break into ions fully, thus any addition of NO2 ions would shift the equilibrium to the molecular form of the acid and the concentration of hydrogen ions would decrease. It would cause the pH to go up.