Hydrated Protoritk of Tin (Sa0,110) precipitates as a white powder on adding together solutions of protochlorido of tin and carbonate of soda.
Senniaride of Tin is funned by mixing fresh precipitated and moist hydrate of peroxide of iron with a solution of protochloride of tin, as free as possible from hydrochlorio acid. By the mutual action of thew substances a slimy gray matter is thrown clown, which is gene rally slightly yellow, from the presence of a little peroxide of iron. It is probably a definite animate of proto.ride of tin (SnO,Sa0„). It Is soluble In hydrucidorie acid, and also in ammonia; which last property distinguishes it from the protoxido ; and it is distinguished from the peroxide by giving a purple precipitate with the salts of gold.
Iliaoride or l'ero.ride of Tin.--One variety of this results from the action of strong nitric acid upon tin. Pried in air, it contains Sn,0,„, 10110; at 212' it loses half its water + 4Aq), and by exposure to a red heat becomes anhydrous and of a straw-yellow colour. It is known in commerce as putty powder, and is used for polishing plate. In the hydrated state it is insoluble in hydrochloric or nitric acids, but is freely dissolved by the alkalies forming salts, which do not crystallise, but which may be obtained in a granular state: that of potash contains MO, Sn,0,„+ 4Aq). It is distinguished from the next form of binoxide of tin by the name me/as/genic acid. When its hydrate) is moistened with protochloride of tin, a beautiful golden-yellow nwlastannats of tin (SnO, is formed.
When carbonate of lime or baryta is added to excess of bichlorido of tin, a gelatinous binoxide is thrown down. Unlike metastannie acid, this variety is readily soluble in nitric or hydrochloric acids. It is called stannic acid, has the formula 110, SnO„ and combines with the alkalies to form crystalline stannales. The staunate of soda (Na0, SnO, + 4Aq) is largely used by the dyer and calico-printer as a nor darting agent. By a heat of 284' Fehr., stannic acid is converted into metastannic acid.
Binoxide of tin renders glass semi-opaque or opalescent, It is au ingredient of most enamels.
Chlorine and Tin combine to form the protochloride and the per chloride. The prolochloride (SnC1+2Aq) is prepared by dissolving the metal in hot hydrochloric acid till the evolution of hydrogen gas ceases : the solution is colourless, and deposits crystals, which some times ore acicular, and at others prisms of considerable size. When hatted to about 212°, the water is nearly expelled; at a higher tempera ture, hydrochloric acid is evolved, and oxiehloride of tin remains. It is soluble in a small quantity of water, but decomposed by a largo quantity, oxichlorido of tin being precipitated.
Tho protochlorido of tin is used as a mordiuit in calico-printing, under the name of salts of tin, and in chemical investigations as a deoxidising agent, acting in tho mode already described.
l'rotochloritle of tin may also be obtained by distilling a mixture of equal weights of granulated tin and bichloride of mercury, or by trans mitting hydrochloric acid gas over tin heated in a glass tube ; in ell these cases it is free from water, and im a gray solid, of a resinous lustre, which fuses below redness and sublimes at a high temperature. It is commonly known as boater of tin.
l'erchloride or Iliddorids of Tin (Sn;) may be prepared In several modes : first, by heating the protochloride iu chlorine gas; second, by dissolving tho hydrated peroxide in hydrochlorio odd; third, by putting tin into the mixture of hydrochlorio and uitrio acid, called aqua regia, which yields nascent chlorine; fourth, when a mixture of 1 part of tin with 4 parts of bichlorido of mercury is distilled with a gentle heat, a colourless limpid liquid is obtained, which fumes strongly in moist air ; this is the bichlorido of tin, formerly known by the name of the fuming liquor of Lihavius. It boils at 239.5° Fehr., is rendered solid by the addition of one-third of its weight of water, and dissolves in a larger quantity. the action of alkalies it is posed, hydrated peroxide of tin being precipitated.