•   Dip one washer in the beaker of 10 mL of HCl with the Cu wire and observe    the reaction, approximately 90 sec. Continue the reaction until the surface is    gray.      Zn (s) + 2 HCl              H2(g) + ZnCl2 (aq) •   Remove the washer from the acid and rinse with distilled water. Dry the washer    on the filter paper.