The precipitated indium hydroxide is converted into a basic sulphite by boiling with excess of sodium bisulphite, and then into the normal sulphite by dissolving in hot sulphurous acid.
Crude acetone may be purified by converting it into the crystalline sodium bisulphite compound, which is separated by filtration and then distilled with sodium carbonate.
It undoubtedly contains a keto-group, for it reacts with hydrocyanic acid, hydroxylamine, phenylhydrazine and ammonia; sodium bisulphite also combines with it to form a crystalline compound, hence it contains the grouping CH 3 ï¿½CO-.
Phenanthrenequinone).Alizarin black,C l oH 4 (OH) 2 0 2 NaHS03, the sodium bisulphite compound of 7.8 dioxy-anaphthoquinone, is a dyestuff used for printing on cotton in the presence of a chromium mordant The naphthoquinone is prepared by the action of zinc and concentrated sulphuric acid on a-dinitronaphthalene.
It combines with sodium bisulphite and with hydrocyanic acid.