Question

A gaseous alkane is burned completely in oxygen. The volume of the carbon dioxide that forms equals twice the volume of the alkane burned (the volumes are measured at the same temperature and pressure). Name the alkane and write a balanced equation for its combustion.

Short answer

Ethane is the alkane for this equation. The balanced equation for this combustion is as follows

${\text{C}}_{\text{2}}{\text{H}}_{\text{6}}\text{+}\frac{\text{7}}{\text{2}}{\text{O}}_{\text{2}}\to {\text{2CO}}_{\text{2}}{\text{+3H}}_{\text{2}}\text{O}$

Step-by-step solution

Balanced equation.

Ethane${\text{C}}_{\text{2}}{\text{H}}_{\text{6}}$ is an alkane that, when burned in oxygen, expands to double its original volume ${\text{CO}}_{\text{2}}$.

The reaction's equation is as follows

${\text{C}}_{\text{2}}{\text{H}}_{\text{6}}\text{+}\frac{\text{7}}{\text{2}}{\text{O}}_{\text{2}}\to {\text{2CO}}_{\text{2}}{\text{+3H}}_{\text{2}}\text{O}$

Another way.

It could also be balanced in this way

${\text{2C}}_{\text{2}}{\text{H}}_{\text{6}}{\text{+7O}}_{\text{2}}\to {\text{4CO}}_{\text{2}}{\text{+6H}}_{\text{2}}\text{O}$

Thus the alkane is ethane.