Cerium(IV) hydroxide, also known as ceric hydroxide, is an inorganic compound with the chemical formula Ce(OH)<sub>4</sub>. It is a yellowish powder that is insoluble in water but soluble in concentrated acids.
Production
Cerium(IV) hydroxide can be produced by reacting cerium(III) carbonate and acetic acid, then oxidizing it with hydrogen peroxide in base. The reactions are:
Ce<sub>2</sub>(CO<sub>3</sub>)<sub>3</sub> + 6 CH<sub>3</sub>COOH â 2 Ce(CH<sub>3</sub>COO)<sub>3</sub> + 3 CO<sub>2</sub>â + 3 H<sub>2</sub>O
2 Ce(CH<sub>3</sub>COO)<sub>3</sub> + 3 H<sub>2</sub>O<sub>2</sub> + 4 H<sub>2</sub>O â 2 Ce(OH)<sub>3</sub>(OOH) + 6 CH<sub>3</sub>COOH
CH<sub>3</sub>COOH + NaOH â CH<sub>3</sub>COONa + H<sub>2</sub>O
2 Ce(OH)<sub>3</sub>(OOH) â 2 Ce(OH)<sub>4</sub>â + O<sub>2</sub>âÂÂ
The net equation isï¼Â
Ce<sub>2</sub>(CO<sub>3</sub>)<sub>3</sub> + 6 CH<sub>3</sub>COOH + 3 H<sub>2</sub>O<sub>2</sub> + 6 NaOH âÂÂ<u><sup>343 K</sup></u>â 2 Ce(OH)<sub>4</sub> + 6 CH<sub>3</sub>COONa + O<sub>2</sub>â + 3 CO<sub>2</sub>â + 5 H<sub>2</sub>O
If using cerium(III) nitrate as ingredient, a similar reaction occurs:
2 Ce(NO<sub>3</sub>)<sub>3</sub> + 3 H<sub>2</sub>O<sub>2</sub> + 6 NH<sub>3</sub>÷H<sub>2</sub>O â 2 Ce(OH)<sub>3</sub>(OOH)â + 6 NH<sub>4</sub>NO<sub>3</sub> + 2 H<sub>2</sub>O
2 Ce(OH)<sub>3</sub>(OOH) âÂÂ<u><sup>ÃÂ</sup></u>â 2 Ce(OH)<sub>4</sub>â + O<sub>2</sub>âÂÂ
It might also prepared by addition of sodium hydroxide or ammonium hydroxide to a Ce<sup>4+</sup> solution, being obtained as a gelatinous precipitate described as CeO<sub>2</sub>÷xH<sub>2</sub>O, (x = 0.5âÂÂ2). Boiling an insoluble Ce<sup>4+</sup> salt in NaOH gives granular Ce(OH)<sub>4</sub>.
References