Calculate the volume of ${\mathrm{O}}_2$ needed for combustion of 1 kg of carbon at STP conditions.

$\mathrm{C}+{\mathrm{O}}_2\stackrel{∆}{\to }{\mathrm{CO}}_2$ 

One mole of C reacts with one mole of O₂ or 12 g of C reacts with 32 g of O₂ (or one mole of O₂).

Volume occupies by one mole of gas at STP is 22.4 L. Volume of gas occupies by burning 1 kg of C is calculated as:

$\mathrm{Volume} \mathrm{of} \mathrm{gas}=1 \mathrm{kg}\times \frac{1000 \mathrm{g}}{1 \mathrm{kg}}\times \frac{22.4 \mathrm{L}}{12 \mathrm{g}}=1866.67 \mathrm{L}$