Answer to Question #232818 in Physical Chemistry for ACHINI

Question

 Calculate the pH of an aqueous solution of 0.01 M sodium acetate. State any assumption made in your calculations. (K_a of acetic acid is 1.75 x 10^-5 mol L^-1 at 25 ˚C in water.)

Answer 1

Neglecting [H+], the mass balance equations give [CH3COO ] + [CH3COOH] = 0.01 [CH3COOH] = [OH ] + [HCO3 ] Without carbonic acid we get [CH3COOH] = [OH ] and [CH3COO ]=0.1; then[OH ]2 = 0.01×10 ^-9.24 and pH = 8.9