Given: C= 81.70% = 81.70g
H = 18.29% = 18.29g
The number of moles is given by: n= Given mass (m)/Molar Mass (M)
M of C = 12 g/mol
M of H = 1 g/mol
Thus, the number of moles of carbon = 81.70g / 12gmol= 6.83moles
and, the number of moles of hydrogen = 18.29/1g/mol = 18.29 moles
The ration of C moles with hydrogen :
H:C = 18.29moles/6.83moles= 2.67 ≈3
Thus, the empirical formula is C3H8
