Potassium dichromate ACS reagent, ≥99.0% _ Potassium dichromate is a red-orange colored solid. Its crystals belong to the triclinic crystal system. On heating above 600°C, it decomposes to give oxygen, potassium chromate and chromium(III) oxide. It acts as a strong oxidizing agent in acidic media. It can be synthesized by the fusion of chromium(III) oxide with potassium carbonate and nitrate or oxygen.