K2Cr2O7 + 7H2SO4 + 6KBr → Cr2(SO4)3 + 3Br2 + 4K2SO4 + 7H2O
Potassium dichromate react with sulfuric acid and potassium bromide to produce chromium(III) sulfate, bromine, potassium sulfate and water. Sulfuric acid - concentrated solution. The reaction takes place in a boiling solution.