Question

An organic compound is estimated through Dumas method and was found to evolved $6$ moles of $CO _{2}, 4$ moles of $H _{2} O$ and 1 mole of nitrogen gas. The formula of the compound is

• A. $C _{6} H _{8} N$
• B. $C _{12} H _{8} N$
• C. $C _{12} H _{8} N _{2}$
• D. $C _{6} H _{8} N _{2}$

Answer 1

Answer: (D)

In Dumas method, organic compound is heated with dry cupric oxide in a combustion tube in the atmosphere of $CO _{2}$. Upon heating, $C$ and $H$ present are oxidised to $CO _{2}$ and water vapours while $N _{2}$ is set free.
Let, the molecular formula of the organic compound ( $1 mol )$ be $C _{x} H _{v} N _{z}$. In Dumas method,

$\therefore$ Molecular formula of the compound is $C _{6} H _{8} N _{2}$.