Zinc, Zn.—It is sold in a granulated form or in sticks. It generally contains over 1 per cent. of lead, with a little iron and arsenic. It is used for separating metals from their solutions, and generally as a reducing agent. For the preparation of hydrogen, and in most other cases, scrap sheet zinc may be used.
Zinc Oxide, ZnO.—The commercial oxide sometimes contains carbonate.
Zinc Sulphate, ZnSO4.7H2O.—It is occasionally used as a standard, and can be purchased nearly pure.
FOOTNOTES:
[6] 3HCl + HNO3 = Cl2 + NOCl + 2H2O.
[7] NaC2H3O2 + HCl = H4C2O2 + NaCl.