An introduction to the study of chemistry / by Ira Remsen.

  • Ira Remsen
Date:
1890
Catalogue details

Licence: Public Domain Mark

Credit: An introduction to the study of chemistry / by Ira Remsen. Source: Wellcome Collection.

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    of the lead salt? Which chlorides are insoluble?] and then passing hydrogen sulphide through the solution. Filter off and add ammonia and ammonium sulphide to the filtrate. Lead forms three distinct compounds with oxygen, yiz.: lead suboxide, Pb,0; lead oxide, PbO; and lead 'peroxide, PbO,. Red-lead, or minium, is apparently a mixture of the oxide and peroxide, and has approximately the compo- sition PbgO^. Lead oxide, PbO, is known by the name of litharge. It is formed by the oxidation of molten lead in contact with the air. When litharge is heated in the air to 400° it takes up oxygen and is converted into the mixture of oxides known as minium, ov red-lead, = -{-VhO^. When heated to a high temperature it gives up oxygen and is again converted into yellow lead oxide. Treated with nitric acid, a part is dissolved forming lead nitrate, while lead peroxide, a brown powder, remains behind. Experiment 175.—Treat a little minium with ordinary dilute nitric acid, and note the change in color. [Does lead pass into solution? How do you know?] Lead peroxide, PbO^, conducts itself somewhat like man- ganese dioxide. When treated with hydrochloric acid chlorine is evolved: PbO, + 4HC1 = PbCl, + 2H,0 + Cl,. Experiment 176.—Treat a little lead peroxide with hy- drochloric acid in a test-tube. [In what form is the lead after the experiment? Is the product soluble or insoluble in water?] Heated with sulphuric acid, oxygen is given off and lead sulphate is formed.