Description

Potassium chromate is the inorganic compound with the formula (K2CrO4). This yellow solid is the potassium salt of the chromate anion. It is a common laboratory chemical, whereas sodium chromate is important industrially.

It is prepared by treating potassium dichromate with potassium hydroxide. In solution, the behavior of potassium and sodium dichromates are very similar. When treated with lead(II) nitrate, it gives an orange-yellow precipitate, lead(II) chromate.

Unlike the less expensive sodium salt, the potassium salt is mainly used for laboratory work in situations where an anhydrous salt is required. It is an oxidizing agent in organic synthesis.

It is used in qualitative inorganic analysis, e.g. as a colorimetric test for silver ions. It is also used as an indicator in precipitation titrations with silver nitrate and sodium chloride (they can be used as standard as well as titrant for each other) as potassium chromate turns red in the presence of excess silver ions.