Question

The answer to each question of this set is a single digit integer, ranging from 0 to 9:

A gas is found to have the molecular formula $(C_3{O}_2{)}_n$. Its vapour density is 34. The value of n will be ........

Answer 1

$Molecularformula=2\times vapourdensity$
$=2\times 34=68$
$n=\frac{molecularformulaweight}{empericalformulaweigh}=\frac{12\times 3}{16\times 2}=1$
So the n is 1