How many grams of Cl are in a 38.0-g sample of the chlorofluorocarbon CF2Cl2

The molecular formula of chlorofluorocarbon is CF₂Cl₂

Molecular mass of CF₂Cl₂ is 120.9 g/mol

Mass of Cl in 1 mol - 2 x 35.5 = 71 g/mol

in 120.9 g of compound - 71 g of Cl

Therefore in 38 g of sample - 71/120.9 x 38 g of Cl

Mass of Cl in 38 g - 22.31 g of Cl