Hydrazine sulfate is the salt of hydrazine and sulfuric acid. It is a white, water-soluble salt of the cation hydrazinium and the anion bisulfate, giving the formula (N₂H₅)HSO₄. It is prepared by treating an aqueous solution of hydrazine with sulfuric acid. It has a number of laboratory uses in analytical chemistry and the synthesis of organic compounds. Hydrazine sulfate is used as a precursor to hydrazine.