Question

A compound has carbon, hydrogen, and oxygen in $3:3:1$ atomic ratio. If the number of moles in $1g$ of the compound is $6.06\times {10}^{-3}$, the molecular formula of the compound will be _____________.

• A. $C_3{H}_{3}O$
• B. $C_6{H}_6{O}_2$
• C. $C_9{H}_9{O}_3$
• D. $C_{12}{H}_{12}{O}_4$

Answer 1

Answer: (C)

$C_9{H}_9{O}_3$

Empirical formula $=C_3{H}_{3}O$

$n=\frac{W}{m}$

$\therefore m=\frac{W}{n}=\frac{1}{6.06\times {10}^{-3}}$

empirical mass $=C_3{H}_{3}O$

$=12\times 3+3\times 1+16\times 1$

$=55$

$\therefore n=\frac{165}{55}=3$

$\therefore$ Molecular formula $=(C_3{H}_{3}O{)}_3$

$=C_9{H}_9{O}_3$

Option $"C"$ correct.