Question

Vapour density of an organic compound is $23$. It contains $52.17\%$ of carbon and $13\%$ of hydrogen. The compound gives iodoform test. The compound is :

• A. Ethanol
• B. Dimethyl ether
• C. Acetone
• D. Methanol

Answer 1

Answer: (A)

We know that, moleculer mass = 2 $\times$ v.d.
$\Rightarrow$ molecular mass of the given organic compound is 46.

	%	Atomic mass	$\frac{\%\text{ composition}}{\text{atomic mass}}$	Wh. one no.ratio
C	52.17	12	4.3475	2
H	13	1	13	6
O	34.83	16	2.176875	1

So, Formula of the compound = $(C_2{H}_{6}O{)}_n$
$n=\frac{46}{46}=1\Rightarrow$ molecular formula is $(C_2{H}_{6}O)$
The compound also gives iodoform test so, it would contain -OH group or
As our molecular formula contains two carbon atoms. So, the organic compound is ethanol.