The molecular formula of the liquid : C₆H₁₂
Further explanation
Given
molar ratio C H = 1.2 : 0.12
0.12 g at STP gave 32 cm³(0.032 L)
Required
The molecular formula
Solution
At STP, 1 mol = 22.4 L, so for 0.032 L :
mol = 0.032 : 22.4
mol = 0.00143
Molar mass (M) of liquid :
M = mass : mol
M = 0.12 g : 0.00143 mol
M = 83.92≈84 g/mol
C : H = 1 : 2
(CH₂)n=84
(12+2.1)n=84
(14)n=84
n=6
(CH₂)₆=C₆H₁₂