Chemical properties of Samarium

The majority of the known compounds of samarium are salts derived from the basic oxide Sm₂O₃. They are pale yellow in colour and the absorption spectra of their solutions exhibit characteristic bands in the blue and violet. Two compounds of the type SmX₂, however, are known, viz., the chloride and iodide.

The equivalent conductivities (λ) of samarium chloride and sulphate solutions at 25° C. indicate that the salts are derived from a fairly strong triacid base (v = litres per gram-equivalent): -

SmCl3	v=	32.59	65.18	130.36	260.72	521.44	1042.9
	λ=	107.2	112.5	120.8	126.1	131.3	135.9
Sm2(SO4)3	v=	31.35	62.70	125.40	250.80	501.60	1003.2
	λ=	31.17	43.49	51.59	61.39	72.76	89.24

The compounds of samarium have been described mainly by Cleve, whose samaria was contaminated with a little europia.