On analysis, a compound with molar mass 60 g mol1 was found to contain 12 g of carbon, 2 g of hydrogen, and 16 g of oxygen. What is the molecular formula of the compound?
Answers
Explanation:
FInd the molecular formula of the compound having 54.5% Carbon, 9.23% Hydrogen. (Vapour density=44g/l, Molar mass=88 g/mol)
The compound has 54.5% Carbon, 9.23% Hydrogen. The remaining is Oxygen.
100 g of the compound will have 54.5 g C, 9.23 g H and 100−54.5−9.23=36.27 g O.
The atomic masses of C, H and O are 12 g/mol, 1 g/mol and 16 g/mol respectively.
The number of moles of C=
12 g/mol
54.5 g
=4.54 mol.
The number of moles of H=
1 g/mol
9.23 g
=9.23 mol.
The number of moles of O=
16 g/mol
36.27 g
=2.27 mol.
Mole ratio C:H:O=4.54:9.23:2.27=2:4:1
The empirical formula of the compound is C
2
H
4
O
The empirical formula mass =2(12)+4(1)+16=44 g/molMolar mass of the compound is 88 g/mol. It is twice the empirical formula mass of 44 g/mol.
The molecular formula of the compound is C
4
H
8
O
2