Mixing 100 mL of 0.200 M ZnCl2 solution with 300 mL of a pH = 7.15?

Mixing 100 mL of 0.200 M ZnCl2 solution with 300 mL of a pH = 7.15 buffer solution causes the precipitation of a white solid. The white solid is Zn(OH)2. Determine what m of zinc hydroxide precipitated. (Enter in mg.)