Question

You need to prepare an acetate buffer of pH 5.52 from a 0.884 M acetic acid solution and a 2.70 M KOH solution. If you have 575 mL of the acetic acid solution, how many milliliters of the KOH solution do you need to add to make a bufer of pH 5.52? The pKa of acetic acid is 4.76.

Answer 1

NO Of mole of aceticacid = M*V

                = 0.575*0.884

                = 0.51 mole

no of mole KOH required = x

pH of acidic buffer = pka + log(base/acid)

5.52 = 4.76+log(x/(0.51-x))

x = 0.434

no of mole KOH required = x = 0.434 mole

volume of KOH required = n/M

                = 0.434/2.7 = 0.161 L
      = 161 ml