Cobalt Hypophosphite, CoH₄(PO₂)₂

Cobalt Hypophosphite, CoH₄(PO₂)₂.6H₂O is readily obtained in aqueous solution by double decomposition of solutions of barium hypophosphite and cobalt sulphate; and by dissolving cobalt hydroxide in hypophosphorous acid. On concentration the salt crystallises out with six molecules of water, but becomes anhydrous at 100° C.