Question

Determine the empirical and molecular formula given the percent compositions or masses.

8.81 g Carbon, 91.2 g Chlorine, Molar mass: 1362.5 g/mol

Answer 1

C$=12.011$ Cl$=35.453$

$8.81g$ Carbon $=\frac{8.81}{12.011}=0.7335moles$

$91.2g$ Chlorine $=\frac{91.2}{35.453}=2.5724moles$

Mole ratio C: Cl $=0.7335:2.5724$

$=1:3.5$

$=2:7$

C₂ Cl₇ has a mass of $2(12.011)+7(35.453)$

$=272.193$

$\frac{1362.5}{272.193}=5.00$

Molecular Formulae $= _5($C₂ Cl₇ $)$

$=$ C$_{10}$ Cl$_{35}$