Ammonium ceric

Ammonium ceric sulphate serves as a powerful oxidizing agent in an acidic medium. The salt has a bright yellow colour and so its solution. On reduction, the resulting cerous salt obtained is colourless in appearance and, therefore, strong solutions may be considered as self-indicating. In general practice, 0.05 N solutions are employed invariably for estimations. As this concentration is very dilute for observation of the respective end-point, hence the inclusion of an appropriate indicator becomes necessary. The oxidation reaction involved may be expressed as follows ... 

It is interesting to observe that the solutions of ammonium ceric sulphate possess a number of advantages over permanganate and dichromate methods discussed earlier in this chapter, viz.,... 

Procedure Weigh accurately about 0.2 g of arsenic trioxide previously dried at 105°C for 1 hour and transfer to a 500 ml conical flask. Wash down the inner walls of the flask with 25 ml of sodium hydroxide solution, swirl to dissolve, add 100 ml of water and mix. Add 30 ml of diluted sulphuric acid, 0.15 ml of osmic acid solution, 0.1 ml of ferroin sulphate solution and slowly titrate with ceric ammonium sulphate solution until the pink colour is changed to a very pale blue. Each 4.946 mg of arsenic trioxide is equivalent to 1 ml of 0.1 N ammonium ceric sulphate or 0.06326 g of Ce(S04)2. 2(NH4)2S04.2H20. 

Calculations Therefore, the normality of ammonium ceric sulphate solution may be expressed as follows ... 

Materials Required Ferrous fumarate 0.3 g diluted H2S04 (10% w/v) 15 ml ferroin sulphate solution 0.1 N ammonium ceric sulphate solution. 

Procedure Weigh accurately about 0.3 g of ferrous fumarate and dissolve in 15 ml of dilute sulphuric acid by the help of gentle heating. Cool, add 50 ml of water and titrate immediately with 0.1 N ammonium ceric sulphate, employing ferroin sulphate solution as indicator. Each ml of 0.1 N ammonium ceric sulphate is equivalent to 0.01699 g of C4H2Fe04. 

Materials Required Acetomenaphthone 0.2 g glacial acetic acid 15 ml dilute hydrochloric acid (10% w/v) 15 ml ammonium ceric sulphate 0.05 N ferroin sulphate solution. 

First, acetamenaphthone (I) undergoes hydrolysis in acidic medium to yield the corresponding phenol and secondly, this phenol is oxidised quantitatively with ammonium ceric sulphate to give the resulting 1, 4-dione derivative (II). 

Ferrous Gluconate 15 g Ferroin sulphate Each ml of 0.1 N ammonium ceric sulphate = 0.04461 g of C12H22Fe014... 

Synonyms ammonium ceric nitrate ammonium hexanitratocerate (IV)... 

On the other hand, chemicals might be chosen as agents for generation of active centers in the polymeric backbone and grafting of monomer in the vapor phase. Ammonium persulfate and styrene (189), acrylic acid (190), butyl acrylate (191), potassium persulfate and n-butyl maleate or 2-ethyl hexyl acrylate (55,134) and ammonium ceric nitrate and methacrylic add (192) are examples of this method. Benzoyl peroxide deposited on polycaprolactam fibers initiates the grafting of styrene in vapor phase (193). 

In general, the acetylenic triple bond is highly reactive toward hydrogenation, hydroboration, and hydration in the presence of acid catalyst. Protection of a triple bond in disubstituted acetylenic compounds is possible by complex formation with octacarbonyl dicobalt [Co2(CO)g Eq. (64) 163]. The cobalt complex that forms at ordinary temperatures is stable to reduction reactions (diborane, diimides, Grignards) and to high-temperature catalytic reactions with carbon dioxide. Regeneration of the triple bond is accomplished with ferric nitrate [164], ammonium ceric nitrate [165] or trimethylamine oxide [166]. 

Ceric nitrate, Ce(N03) 4, is not known as a simple salt, but double nitrates of the type Ce(N03)4 2 M N03 are formed with the alkali metals and ammonium. In aqueous solutions these salts are readily hydrolyzed, but they are the most stable ceric salts. The ammonium ceric nitrate is important in the purification of cerium. A series of double nitrates, M (N03)2 Ce(N03)4 8 H2O, is also formed, but they are less stable than the alkali double salts. When ceric hydroxide is evaporated with nitric acid, crystals of the basic salt 2 Ce0H(N03)2 9 H2O are obtained. 

Ammonium ceric nitrate / , -Ethyleneoxo compds. by cyclobutane ring opening... 

Vinyl-O-heterocyclics. 7-Hydroxy-l-trimethylsilyl-2-heptene in acetonitrile at 0 treated in one portion with 8 eqs. 1 M aq. ammonium ceric nitrate, and quenched with satd. aq. NaCl after a few min- 2-vinyltetrahydropyran. Y 67%. F.e.s. S.R. Wilson, C.E. Augelli-Szafran, Tetrahedron 44, 3983-95 (1988). 

---