The bromine percentage is 49.42 %
Step-by-step explanation:
Mass of AgBr precipitated = 0.31 g
Molecular weight of AgBr = 187.77 g mol - 1
moles of AgBr = 0.31 g by 187.77 g mol - 1 = 0.0016509 moles
moles of Br ion = 0.0016509 moles
Mass of Br ion = 0.0016509 moles into 79.904 g mol - 1 = 0.1319 g
The Total mass of compound = 0.2669 g
Percentage of bromine = 0.1319 by 0.2669 = 49.42 percent
Hence the bromine percentage is 49.42 %