Uranyl hydroxide
Uranyl hydroxide is a hydroxide of uranium with the chemical formula UO(OH) in the monomeric form and (UO)(OH) in the dimeric; both forms may exist in normal aqueous media. Uranyl hydroxide hydrate is precipitated as a colloidal yellowcake from oxidized uranium liquors near neutral pH.
Hydroxide
The hydroxide ion may act as a base catalyst. The base abstracts a proton from a weak acid to give an intermediate that goes on to react with another reagent. Common substrates for proton abstraction are alcohols, phenols, amines, and carbon acids. The p"K" value for dissociation of a C–H bond is extremely high, but the pK alpha hydrogens of a carbonyl compound are about 3 log units lower. Typical p"K" values are 16.7 for acetaldehyde and 19 for acetone. Dissociation can occur in the presence of a suitable base.
The base should have a p"K" value not less than about 4 log units smaller or the equilibrium will lie almost completely to the left.