Question

On combustion of one mole of a hydrocarbon gives two moles of carbon dioxide and two moles of water and a large quantity of heat is produced. The hydrocarbon is

• A. Methane
• B. Ethane
• C. Ethene
• D. Ethyne

Answer 1

The correct option is C

Ethene

Hydrocarbons are made up of Carbon $\left(\mathrm{C}\right)$ and Hydrogen $\left(\mathrm{H}\right)$ atoms connected by a chemical bond.

The combustion reaction is a reaction in which any compound is combusted in the presence of Oxygen to produce a large amount of heat and Carbon dioxide gas $\left({\mathrm{CO}}_2\right)$.

On combustion of one mole of Ethene $\left({\mathrm{C}}_2{\mathrm{H}}_4\right)$, two moles of Carbon dioxide, two moles of water molecules and heat is produced in a very large amount.

Therefore, the hydrocarbon is Ethene.

The chemical equation of combustion reaction of Ethene is written as:

$$\begin{gathered} {\mathrm{CH}}_2={\mathrm{CH}}_2+3{\mathrm{O}}_2\stackrel{\mathrm{Combustion}}{\to }2{\mathrm{CO}}_2+2{\mathrm{H}}_2\mathrm{O}+\mathrm{Heat} \\ \left(\mathrm{ethene}\right)\left(\mathrm{oxygen}\right)(\mathrm{carbon}(\mathrm{water}) \\ \mathrm{dioxide}) \end{gathered}$$

Final answer:

Hence, option (C) is the correct option.