Chromate

Chromate is an ion that contains one chromium ion in its +6 oxidation state and 4 oxide atoms. Its overall charge is -2. Chromate ion is strongly oxidizing in acidic conditions, but weakly oxidizing in basic conditions. Chromates are generally bright yellow. They can be made by reaction of chromium(III) oxide and a metal oxide in a basic environment. The oxygen in the air boosts the chromium atom's oxidation state from +3 to +6.

Chromates are harmful when powdered because the dust is carcinogenic (it can cause cancer). This can be avoided by reducing chromate with something like iron(II) sulfate.

Examples

• Sodium chromate
• Potassium chromate

Other pages

• Chromium
• Dichromate, a similar ion with the chromium in the same oxidation state