This is the stuff that can be used for cooking meth - hypophosphorous acid.
Monograph number: 4916
Title: Hypophosphorous Acid.
CAS Registry number: [6303-21-5]
Molecular formula: H3O2P
Molecular weight: 66.00
Composition: H 4.58%, O 48.49%, P 46.93%.
Literature references: Conveniently prepd by treating NaH2PO2 with an ion-exchange resin: Klement, Z. Anorg. Allgem. Chem. 260, 267 (1949). Review: Ohashi, "Lower Oxo Acids of Phosphorus and Their Salts" in Topics in Phosphorus Chemistry, Vol. 1, M. Grayson, E. J. Griffith, Eds. (Interscience, New York, 1964) pp 113-187.
Properties: The water-free acid forms deliquesc crystals; supercools to a colorless, odorless, oily liquid. d 1.493. mp 26.5 deg. Dec by heat into H3PO4 and spontaneously flammable PH3. Miscible with water, alcohol, ether. Oxidized by hot H2SO4; SO2 and S formed. It is a powerful reducing agent. Marketed in aq solns
of various concns, e.g., 50%, d 1.274; 30-32%, d 1.13; 10%, d 1.04. K1 = 8 x 10-2.
Melting point: 26.5
Density: 1.493; 1.274; 30-32; 1.13; 10; 1.04