Question

Give an equation to show how the following are made from their corresponding anhydrides.
(b) Phosphoric acid

Answer 1

Acidic oxides are also known as acidic anhydride. When such acidic anhydride dissolves in water they produce acid.
The anhydride of phosphoric acid is phosphorus pentoxide $P_2{O}_5$. The chemical equation for the formation of phosphoric acid from phosphorous pentoxide can be given as,
$P_2{O}_5+3H_{2}O\to 2H_{3}P{O}_4$