Sodium hydrogensulphate

The hydrogensulphates (or bisulphates) containing the ion HSO4, are only known in the solid state for the alkali metals and ammonium. Sodium hydrogensulphate is formed when sodium chloride is treated with cold concentrated sulphuric acid ... 

When solid sodium hydrogensulphate is heated, sodium pyro-sulphate is formed further heating gives sodium sulphate and sulphur trioxide ... 

A mixture of ethanol and acetic anhydride detonated and the compounds combusted causing a fire when sodium hydrogensulphate was introduced into the mixture by mistake. The acid nature of this salt obviously catalysed this alcoholysis. 

Fusions with (a) sodium carbonate or fusion mixture, (b) borax and lithium metaborate, (c) alkali bifluorides, and (d) alkali hydrogensulphates (slight attack in the last case above 700 °C, which is diminished by the addition of ammonium sulphate). 

Hydride ion transfer from formic acid and its salts finds widespread application in the reduction of organic substrates, but limited use has been made of the procedure under phase-transfer catalytic conditions. However in the presence of a ruthenium complex catalyst, it is possible to selectively reduce the C=C bonds of conjugated ketones with sodium formate [11], The rate of reduction is fastest with tetrahexyl-ammonium hydrogensulphate and Aliquat the complete reduction of chalcone being effected within one hour, whereas with benzyltriethylammonium chloride only ca. 15% reduction is observed after two hours under similar conditions. 

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