The nionohydrate of Pentachlor-hydroxy-platinic Acid, H2PtCl5(OH), namely, H2PtCl5(OH).H2O, is obtained as a deliquescent residue on keeping crystals of hexachlor-platinic acid in a vacuum over caustic potash at 100° C. for three days:
H2PtCl6.6H2O = H2PtCl5(OH).H2O + HCl + 4H2O.
It readily dissolves in water, yielding a yellow solution with an acid reaction, sufficiently powerful to decompose carbonates. With ammonia no precipitate is obtained, which property serves to distinguish this acid from hexachlor-platinic acid. With ammonium chloride or potassium chloride the corresponding hexaehlor-platinate is produced.
Titration with alkali, using phenolphthalein as indicator, shows that the acid is dibasic, and several salts have been prepared. |