Question

Quantitative analysis of an organic compound gave the following results.
Percentage of carbon = 92.3 and percentage of hydrogen = 7.7
If the molecular weight of the compound is 78. Calculate its molecular formula.

Answer 1

Given,

Percentage of carbon$=92.3\%$

Percentage of oxygen$=7.7\%$

Hence, mass of carbon$=0.923\times 78=71.994$

moles of carbon$=\frac{71.994}{12}=6$

moles of oxygen$=\frac{78-71.994}{1}=6$

Hence molecular formula of the compound$=C_6{H}_6$