Ka for HAc = 1.8x10^-5 pKa = 4.74 pH = pKa + log(Ac-/HAc) 5.40 = 4.74 + log(Ac-/HAc) log(Ac-/HAc) = 0.66 Ac-/HAc = 4.57 Ac : HAc = 4.57 : 1 (5.57 total ) 1000 mL / 5.57 = 179.5 4.57 x 179.5 = 820 mL 1.00 x 179.5 = 180 mL
820 mL 0.1 M sodium acetate 180 mL 0.1 M acetic acid
