The molar mass of HBr is equal to about 80.91 grams per mole. The molar mass is found by adding together the atomic mass of one atom of bromine, which is 79.90 grams per mole, and one atom of hydrogen, which is about 1 gram per mole.
HBr is the chemical formula for hydrogen bromide. When dissolved in an aqueous solution, hydrogen bromide becomes hydrobromic acid, which is also commonly represented with the formula HBr. Hydrobromic acid is a strong acid, with a pKa value of minus nine. It can be formed through a reaction between sulfuric acid and potassium bromide. The acid HBr has a pale yellow color.