Question

How many grams of Br are in 255 g of CaBr2?

Answer 1

Molar mass:

Br = 79.904 g/mol
CaBr2 = 199.886 g/mol

CaBr2 = 2 Br + Ca

199.886 g --------------- 2 x 79.904 g
255 g -------------------- ?? ( mass of Br )

255 x 2 x 79.904 / 199.886 =

 40751.04 / 199.886 =>203.87 g of Br

hope his helps!