Question

$C{O}_2$ and $N_2$ are non-supporters of combustion. However, for putting out fires, $C{O}_2$ is preferred over $N_2$ because $C{O}_2$ :

• A. does not burn
• B. forms non-combustible products with burning substances
• C. is denser that nitrogen
• D. is a more reactive gas

Answer 1

The correct option is C is denser that nitrogen

Nitrogen is a lighter gas than oxygen. Due to this, nitrogen rests above oxygen and therefore, the contact between oxygen and fire still exists and hence, the fire cannot be controlled. However, since carbon dioxide is denser than oxygen, carbon dioxide will occupy the region between fire and oxygen and will thus, remove the contact between fire and oxygen. Hence, it can help to put out the fire.