Question

What is the empirical formula for a compound if a sample contains 3.72 g of P and 21.28 g of Cl

Answer 1

M(P)=3.72 g
M(P)=31 g/mol

m(Cl)=21.28 g
M(Cl)=35.5 g/mol

n(P)=m(P)/M(P)
n(P)=3.72/31=0.12 mol

n(Cl)=m(Cl)/M(Cl)
n(Cl)=21.28/35.5=0.60 mol

P : Cl = 0.12 : 0.60 = 1 : 5

PCl₅ - is the empirical formula