Ceric oxide

Cerium Oxide. The most stable oxide of cerium is cerium dioxide [1306-38-3] Ce02, also called ceria or ceric oxide. When cerium salts are calcined in air or if oxygen is present, this tetravalent Ce(IV) oxide is formed, cerium sesquioxide [1345-13-7] can be prepared in strongly reducing... 

Hydroxide. Freshly precipitated cerous hydroxide [15785-09-8] Ce(OH)2, is readily oxidized by air or oxygenated water, through poorly defined violet-tinged mixed valence intermediates, to the tetravalent buff colored ceric hydroxide [12014-56-17, Ce(OH)4. The precipitate, which can prove difficult to filter, is amorphous and on drying converts to hydrated ceric oxide, Ce02 2H20. This commercial material, cerium hydrate [23322-64-7] behaves essentially as a reactive cerium oxide. 

Ceri-oxyd, n. ceric oxide, cerium(IV) oxide, -salz, rt. ceric salt, cerium(IV) salt. sulfat, n. ceric sulfate, cerium(IV) sulfate. 

Ceric Oxide (Cerium Dioxide, Cerium Oxide, Ceria). CeOj, mw 172.13, white powd, mp ca 2600°, d 7.132g/cc at 23°. Sol in coned sulfuric and nitric acids, insol in dil acids and w. Prepn is by dissolving CeCOj in 16N HNOa contg 3% H202 and then evapg off the nitrate soln followed by thermal decompn. The yield is 97.6% of 99.8% pure Ce02, The oxide is used in optics, electronics, as a diluent in nuclear fuels (as... 

Ceric ammonium sulfate, 5 674 Ceric fluoride, 5 674 Ceric hydroxide, 5 676 Ceric oxide, 5 670, 675 Ceric rare earths (RE), 74 631 Ceric sulfate, 5 674 Ceric sulfate method, for tellurium determination, 24 415 Cerium (Ce), 5 670-692 74 630, 63 It, 634t. See also Cerium compounds analysis, 5 679-680 color, 7 335... 

The metal is stable in dry air at ordinary temperatures. Upon heating, it converts to ceric oxide, Ce02. The finely divided metal may ignite spontaneously. It is oxidized in moist air at ambient temperatures. It reacts with water forming cerium(III) hydroxide. 

Formula Ce02 MW 172.11 Synonyms ceria ceric oxide... 

Third example - Although ceric oxide really represents the active element in polishing media, most of the polishing plants are satisfied with about 50 % pure ceric oxide, which is available in the natural mixture of the light rare eai h elements as they are extracted either from bastnasite or monazite, in order to keep the cost of the product low. 

Replacement of ceric oxide by tin oxide or zirconium oxide as opacifiers for enamels. 

Further work by Cornish and Watt ( ) and Silvernail and Goet-zinger ( ) established the active role played by the presence of water, and these authors concluded that a chemical-mechanical hypothesis would fit the observed data. In the case of ceric oxide polishing of glass, Cornish and Watt suggest the formation of a "CeO-Si" activated complex which permits the rupture of the O-Si-0 bonds by hydrolysis. The complex "CeO-Si" then breaks apart, the hydrated silica is swept away along with alkalis released from the glass surface, and the process repeats. 

I suggested to Father Moses that we soon have a paper on cerium for the Annalen. He laughed rather scornfully, went down into his laboratory, for he lives in the house of the Academy, and brought up a mortar half full of a white, slightly yellowish powder, and asked, What is that I admitted my ignorance. That, Sir, he said, is the way ceric oxide looks when one has it pure... 

Cerium Dioxide. See Ceric Oxide under Oxides... 

Ceric Oxide from Cerous Oxalate, Ce02... 

Cerous oxalate, Ce2(C2O4)3-10H2O, is formed in the Welsbach treatment of Monazite sands in the production of thorium nitrate, and is the starting point in the preparation of nearly all cerium salts. Since ceric oxide is more easily acted upon by common reagents, it is often prepared as the first step in making other salts from the oxalate. 

If cerous oxalate is strongly heated in air, the water of crystallization is first driven off, then the cerous oxalate decomposes into cerous oxide and oxides of carbon. The cerous oxide is oxidized by the oxygen in the air to ceric oxide. 

In the quantitative determination of cerium, use is made of the fact that cerous oxalate is insoluble in neutral and acid solution. Since a quantitative yield is not necessary in this preparation, some of the cerium is sacrificed to insure complete removal of any iron that may be present. In order to have a neutral solution for the hydrolysis of the iron, a slight excess of ceric oxide is used. 

From the discussion of the preparation of ceric oxide it is evident that the cerous oxide, Ce203, which would be the direct... 

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... 

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