Thallous sulphite, Tl₂SO₃

Thallous sulphite, Tl₂SO₃, may be prepared by adding sulphurous acid to thallous hydroxide or by mixing solutions of thallous sulphate and sodium sulphite, when thallous sulphite is precipitated. It forms white crystals of density 6.427 at 20°, and is insoluble in alcohol. It can be recrystallised from warm water; 100 parts of water at 15° dissolve 3.34 of the salt.