Question

Analysis of a sample of a covalent compound showed that it contained 14.4% hydrogen and 85.6% carbon by mass. what is the empirical formula for this compound?

Answer 1

w(C)=0.865
A(C)=12
w(H)=0.144
A(H)=1

CxHy
M(CxHy)=12x+y

w(C)=xA(C)/(12x+y)
w(H)=yA(H)/(12x+y)

solve a system of two equations with two unknowns
12x/(12x+y)=0.856
y/(12x+y)=0.144

x=1
y=2

CH₂ is the empirical formula