Monopotassium arsenate is the inorganic compound with the formula KH<sub>2</sub>AsO<sub>4</sub>. A white solid, this salt is used to prepared other arsenic-containing compounds, mainly pesticides. It is prepared by calcining arsenic oxide and potassium nitrate, followed by extraction with water.
Relevant acid-base equilibria for aqueous solutions of this diprotic acid derived from arsenic acid are as follows: