If 2 litres of butane is completely burnt the volume of ${CO}_2$ obtained under the same conditions would be

When butane is burnt completely in the presence of oxygen it forms carbon dioxide and water as the residue.

The balanced chemical equation of the following reaction is,

$2{\mathrm{C}}_4{\mathrm{H}}_{10}+13{\mathrm{O}}_2\to 8{\mathrm{CO}}_2+10{\mathrm{H}}_2\mathrm{O}$

2 moles of butane gives 8 moles of carbon dioxide.

So, the volume of ${\mathrm{CO}}_2$ obtained from 2 liters of butane is 8 liters.

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