14HBr + K2Cr2O7
2CrBr3 + 3Br2 + 7H2O + 2KBr
Hydrogen bromide react with potassium to dichromate produce chromium(III) bromide, bromine, water and potassium bromide. Potassium to dichromate - solid; hydrogen bromide - concentrated solution. This reaction takes place at a temperature of 60-80°C.