Question

How many grams of F are there in a 36.01 g sample of CrF3 given that 18.83 g of this sample are Cr?

Answer 1

Ca = 40.1

2 F = 38.0

--------------

78.1

% F = 38.0/78.1

Now you can calculate mass of F

0.487 ( 255 g ) = 124 g F