Ceric nitrate, Ce(NO₃)₄

Ceric nitrate, Ce(NO₃)₄, has not been isolated. By evaporating a solution of ceric hydroxide in concentrated nitric acid, in the presence of a considerable quantity of calcium nitrate, red monoclinic crystals (a:b:c = 1.7834:1:1.0465; β = 90°48') of basic ceric nitrate, 2Ce(OH)(NO₃)₃.9H₂O, can be obtained. The aqueous solution of the salt readily undergoes hydrolysis.

Ceric nitrate forms an isomorphous series of double nitrates with the nitrates of potassium, rubidium, caesium, and ammonium. They are of the type Ce(NO₃)₄.2MNO₃, and form anhydrous, orange-red, monoclinic crystals: -

	a	b	c	β
Ce(NO3)4.2KNO3	1.2455	1	1.9170	91°12'
Ce(NO3)4.2(NH4)NO3	1.1690	1	1.9260	90°21'

The salts are readily soluble in water and alcohol, but much less soluble in fairly concentrated nitric acid. In aqueous solution they are hydrolysed in a similar manner to ceric nitrate. It is probable that the solutions contain not only the ions Ce^••••, M^•, and NO₃', but also the complex ion Ce(NO₃)₆''; indeed, in alcoholic solution it has been shown by migration experiments that a coloured cation is present.