Preparation of chromium(III) bromide
15 g of chromium(III) oxide and 6 g of charcoal are ground together with just enough starch paste to yield a very viscous plastic mass. The starch paste may be prepared by boiling 100 ml of water with about 10 g of soluble starch until no more dissolves, decanting the solution from any undissolved material and allowing it to cool. The chromium(III) oxide-carbon mass is shaped into pellets 6-10 mm in diameter and dried thoroughly at 100° C. The brittle pellets are placed in an open combustion tube and heated for one hour at 500° C in a circular oven. The obtained mass is placed in the center of a combustion tube and the latter is placed in a tube oven with temperature control. 25 ml of bromine are placed in a distilling flask fitted with an inlet for carbon dioxide. The side arm of the flask is attached to the combustion tube. A slow stream of carbon dioxide is passed through the bromine warmed to 50° C in a water bath. The exit end of the combustion tube is fitted with a wide-mouth receiver that carries an outlet tube for the carbon dioxide. The reaction is maintained at 600-700 °C until all the bromine has been volatilized; the dark olivegreen scale of product partially sublimes into the cooler end of the tube and receiver in almost quantitative yield.
Inorganic laboratory preparations, by G. G. Schlessinger, 21, 1962
chromium(3+) tribromide, Chromium(III) bromide, Chromium bromide(CrBr3), UNII-WZB719DDER, WZB719DDER, AC1L335G, CTK3J8772, AR-1I2315, IN001121, IN005788
Chromium tribromide, CID82309, 10031-25-1, 100753-38-6