286 ELEMENTS OF GROUP IV50 cc. of boiling water, filter if necessary, and pour into the hot
solution of cerous chloride while stirring. Boil for 1 minute,
filter hot, using suction. Wash the precipitate on the filter with
two successive 10-cc. portions of ammonium oxalate solution.
Dry on paper towels, weigh, and put up in a 2-ounce cork-stop-
pered bottle.
QUESTIONS
- Explain at what point in the preparation and how the eerie
compound was reduced to cerous. - Explain how the separation of iron depends on the difference
in the extent to which ferric and cerous salts hydrolyze. Which
is more basic, Fe(OH) 3 or Ce(OH) 3?
PREPARATION 51
CEROUS CHLORIDE, CeCl 3 -7H 2 O
Ceric oxide dissolves in hydrochloric acid, forming cerous
chloride and evolving chlorine. (Read the discussion of Prepara-
tion 50.) The cerous chloride hydrolyzes to only a slight extent
in neutral solution. By evaporating and cooling the solution,
crystals of CeCl 3 -7H 2 O may be separated if hydrolysis is prevented.
A saturated solution at room temperature contains 128 grams of
CeCl 3 -7H 2 O in 100 cc. of solution, and the solubility increases
rapidly with rise in temperature. The salt is soluble in its own
water of crystallization at a temperature below the boiling point.
Materials: CeO 2 , 48 grams = 0.25 F.W. + 5 grams.
12ATHCl,84cc. = 1F.W.
sodium carbonate, anhydrous.
Apparatus: 2-liter common bottle.
500-cc. flask.
5-inch funnel.
8-inch porcelain dish.
4-inch crystallizing dish.
5-inch watch glass,
iron ring and ring stand.
Bunsen burner.Procedure: Dilute 84 cc. of 12 N HC1 to 125 cc. and pour it into
the 500-cc. flask. Add the ceric oxide under a hood. Warm