Question

What is the volume of oxygen required for complete combustion of 0.25 mole of methane at S.T.P.?

• A. 22.4 L
• B. 5.6 L
• C. 11.2 L
• D. 7.46 L

Hint:

Use the mole ratio from the balanced equation and remember that 1 mole of gas at STP occupies 22.4 L.

Answer 1

The Correct Option is C

The balanced chemical equation for the combustion of methane is: \[ \mathrm{CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O} \] This shows 1 mole of methane requires 2 moles of oxygen for complete combustion. At S.T.P., 1 mole of any gas occupies 22.4 L. So, 2 moles of oxygen occupy: \[ 2 \times 22.4 = 44.8\ \text{L} \] Therefore, for 0.25 moles of methane, the volume of oxygen required is: \[ 0.25 \times 44.8 = 11.2\ \text{L} \]