If 4.57 grams of AgBr was isolated in a gravimetric analysis of a 9.30 gram sample, what is the % Br- by weight in the samples?

please provide steps to get to answer

2 answers

What is the mass of Br?
moles AgBr = 4.57 grams AgBr x (1 mol AgBr/molar mass AgBr).

There is 1 mole Br in 1 mole AgBr; therefore, you now have moles Br.

How many grams Br do you have?
grams Br = moles Br x atomic mass Br

What percent is that of the original sample?
%Br = (grams Br/mass sample)*100 = ??
1.94%