Organic acid anhydride case, the name of the acyl group is enclosed in parentheses to avoid ambiguity in the name, e.g., (thioacetic) anhydride (CHC(S)OC(S)CH). When two acyl groups are attached to the same sulfur atom, the resulting compound is called a thioanhydride, e.g., acetic thioanhydride ((CHC(O))S). Organic acid anhydride An organic acid anhydride is an acid anhydride that is an organic compound. An acid anhydride is a compound that has two acyl groups bonded to the same oxygen atom. A common type of organic acid anhydride is a carboxylic anhydride, where the parent acid is a carboxylic acid, the formula of the anhydride
Pyrosilicic acid the original solution is converted to pyrosilicic acid, which persists for 10 minutes or more. Pyrosilicic acid can also be obtained by controlled hydrolysis of the corresponding organic ester, such as hexaethyl pyrosilicate, with dilute sulfuric acid. Pyrosilicic acid Pyrosilicic acid is the chemical compound with formula , or -O-. It is one of the silicic acids. It has never been isolated in pure form, but it is assumed to be present in solutions of silicon dioxide (silica) in water, in equilibrium with other silicic acids and silicate ions. The salts of pyrosilicic acid are called pyrosilicates, such as sodium