A sample of gallium bromide, GaBr3, weighing 0.165 g was dissolved in water and treated with silver nitrate, AgNO3, resulting in the precipitation of 0.299 g AgBr. Use these data to compute the %Ga (by mass) GaBr3.
Step 1: Calculate the amount of Br from AgBr (since all of the Br from GaBr3 is converted to AgBr):
Molar mass AgBr = mass Ag + mass Br
Molar mass AgBr = 107.87 g/mol + 79.9 g/mol = 187.77 g/mol