Question

1 volume of a gaseous compound requires 2 volumes of $O_{2}$ for combustion and gives 2 volumes of $CO_{2}$ and 1 volume of $N_{2}$. Determine the molecular formula of the compound.

Answer 1

From the given,

One volume of gaseous compounds required two volumes of ${ O }_{ 2 }$ to form two volumes of ${ CO }_{ 2 }$ and one volume of ${ N }_{ 2 }$.

Here, we considered unknown gaseous compound is “x”

$x\quad +\quad 2{ O }_{ 2 }\quad \rightarrow \quad 2C{ O }_{ 2 }\quad +\quad { N }_{ 2 }\\ \\(CN{ ) }_{ 2 }\quad +\quad 2{ O }_{ 2 }\quad \rightarrow \quad 2C{ O }_{ 2 }\quad +\quad { N }_{ 2 }$

$(CN{ ) }_{ 2 }$ called cyanogen it is a gaseous compound.

Combustion of cyanogen gives volumes of ${ O }_{ 2 }$  to form 2 volumes of ${ CO }_{ 2 }$  and 1 volume of ${ N }_{ 2 }$

Therefore, molecular formula of gaseous compound is $(CN{ ) }_{ 2 }$