Question

Carbon compound containing only $C$ and $O$ has an approximate molecular mass of 290 analysis it is found to contain 50% by mass of each element. What is molecular Formula of the compound?

• A. $C_{12}{O}_8$
• B. $C_2{H}_2$
• C. $C_6{H}_6$
• D. $C_{12}{O}_9$

Answer 1

The correct option is D $C_{12}{O}_9$

The empirical formula $=C_4{O}_3$

Mass $=(4\times 12)+(3\times 16)=96$

Molecular mass $=290$

$\therefore$ $n=\frac{290}{96}=3$ (approx)

Molecular formula $=n\times$ Empirical formula

$=3\times C_4{O}_3$

$=C_{12}{O}_9$