Question

In an experiment, 4.14 g of phosphorus combined with chlorine to produce 27.8 g of a white solid compound. what is the empirical formula of the compound?

Answer 1

Grams of Phosphorus = 4.14 grams 
Grams of white compound = 27.8 grams 
Grams of Chlorine would be = 27.8 - 4.14 = 23.66 grams
 Calculating moles which would be grams / molar mass
 Molar mass of P = 30.97 grams / moles; Molar mass of Cl = 35.45 grams / moles
 Moles of Phosphorus = 4.14 grams / 30.97 grams / moles = 0.1337 moles
 Moles of Chlorine = 23.66 grams / 35.45 grams / moles = 0.6674 moles
 Calculating the ratios by dividing with the small entity
 P = 0.1337 moles / 0.1337 moles = 1
 Cl = 0.6674 moles / 0.1337 moles = 5 
So the empirical formula would be PCl5