Question

$10$ g of an organic compound on complete combustion gives $17.6$ g $C{O}_2$, $3.6$ g water and $6.4$ g $S{O}_{2.}$ The empirical formula of the compound is :

• A. $C_4{H}_{4}SO$
• B. $C_3{H}_{4}SO$
• C. $C_4{H}_{8}SO$
• D. $C_2{H}_{4}SO$

Answer 1

Answer: (A)

$C_4{H}_{4}SO$

$10$ g of an organic compound on complete combustion gives $17.6$ g $C{O}_2$, $3.6$ g water and $6.4$ g $S{O}_2$.

$100$ g of an organic compound on complete combustion will give $176$ g (or $4$ moles) $C{O}_2$, $36$ g (or $2$ moles) water and $64$ g ($1$ mol) $S{O}_2$.

$1$ mol of water contains $2$ mol of $H$.

Thus, the number of moles of $C,H$ and $S$ present in $100$ g of sample are $4,4$ and $1$ respectively.

The amount of oxygen present in the sample is $100-(48+4+32)=16$ g or, $1$ mole.

Thus the empirical formula of the substance is $C_4{H}_{4}SO$.

Hence, option $A$ is correct.