Question

Are hydrocarbon vapours heavier than air?

Answer 1

No, not all hydrocarbons are heavier than air.

1. Hydrocarbon- In organic chemistry, hydrocarbon is an organic compound which contains carbon and hydrogen as its constituent elements.
2. Methane $\left({\mathrm{CH}}_4\right)$ gas is lighter than air. Ethylene $\left({\mathrm{CH}}_2={\mathrm{CH}}_2\right)$ and Acetylene $\left(\mathrm{CH}\equiv \mathrm{CH}\right)$ gases are also lighter than air. These compounds have a low molecular formula and are hence termed as light hydrocarbons. They are less denser than air.
3. Heavy hydrocarbons contain a mixture of hydrocarbons (long chains of carbon units interlinked with one another). They have high molecular masses and are denser than air. Crude oil and petroleum products are heavier than air.
4. Example of hydrocarbons which are heavier than air includes Butane $\left({\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_3\right)$ and Ethane $\left({\mathrm{CH}}_3{\mathrm{CH}}_3\right)$ vapours.