Zinc, Activated

Place the zinc cylinders or pellets to be activated in a conical flask and add a sufficient quantity of a 50 ppm solution of chloroplatinic acid to cover the metal. Allow the metal to remain in contact with the solution for 10 minues, wash, drain and dry immediately.

Arsenic(2.4.2, Method A) To 5 g of the activated zinc add 15 mL of hydrochloric acid, 25 mL of water, 0.1 mL of stannous chloride solution and 5 mL of potassium iodide solution. No stain is produced on the mercuric bromide paper.

Activity Repeat the test for arsenic using the same reagents and adding a solution containing 1 μg of arsenic. An appreciable stain appears on the mercuric bromide paper.