Potassium dichromate (K2Cr2O7). Molar mass 294.185 g/mol. Also known as potassium bichromate, bichromate of potash, dipotassium dichromate, dichromic acid, dipotassium salt, chromic acid, dipotassium salt, lopezite and potassium dichromate VI. Potassium dichromate is a common inorganic chemical reagent used as an oxidizing agent with applications in laboratory and industrial. A solution in water can be used to distinguish aldehydes from ketones, as aldehydes will change the colour from orange to green. This chemical is very harmful to health.