Ammonium hexachlorostannate

Reactions of tin(lV) ions To study these reactions use a 0-25m solution of ammonium hexachlorostannate(IV) by dissolving 92 g (NH4)2[SnCl6] in 250 ml concentrated hydrochloric acid and diluting the solution to 1 litre with water. 

Twelve grams of stannous chloride 2-hydrate are dissolved in 76ml of 3Af hydrochloric add contained in a 250ml suction flask fitted with a stopper and gas delivery tube leading well under the surface of the solution. The flask and contents are immersed in an ice hath and chlorine is passed in (2-8 bubbles/sec) until oxidation is complete. This is indicated by a persistent yellow color in the reaction mixture due to excess chlorine. The chlorination will take 15 to 30 minutes at the above rate of introducing the gas. The solution of hexachlorostannic (IV) acid is now warmed to 50°C and a solution of 6g of ammonium chloride in 25ml of 3Af Hydrochloric add at the same temperature are mixed together. The warm solution is evaporated to crystallization on the steam bath, cooled, filtered by suction, and drained well. The complex salt is dried in vacua over solid alkali. The mother liquor is worked up for further batches of crystals. 

Thirteen grams of stannic chloride (No. 84 CAUTION Fuming corrosive liquid—hood ) are weighed into a small stoppered flask and then poured slowly with good stirring into 75ml of 3Af hydrochloric acid cooled in ice. The dear solution of hexachlorostannic (IV) acid is treated with ammonium chloride at 50°C as described in (I) and the complex salt is isolated in similar yield. 

The hexachloroplumbate salts MaPbClg represent a convenient and stable source of lead(IV). A solution of H2PbCl6 is easily produced by the action of chlorine upon a fine suspension of lead(II) chloride in concentrated hydrochloric acid. Subsequent addition of solutions of either ammonium or potassium chloride produces the corresponding M2PbCl6 salt as lemon yellow crystals. The alkali hexachloroplumbates are isomorphous with the hexachlorostannates. 

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