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:

At STP, 1 mole of any gas occupies 22.4 L. Use this to calculate the volume of gases involved in chemical reactions.

Answer 1

The Correct Option is A

The balanced chemical equation for the combustion of methane (CH4) is: \[ CH_4 + 2 O_2 \rightarrow CO_2 + 2 H_2O \] From the equation, we see that 1 mole of methane reacts with 2 moles of oxygen. Therefore, 0.25 moles of methane will require: \[ 0.25 \, \text{mol CH}_4 \times 2 \, \text{mol O}_2/\text{mol CH}_4 = 0.5 \, \text{mol O}_2 \] At standard temperature and pressure (S.T.P.), 1 mole of any gas occupies 22.4 L. Therefore, the volume of oxygen required is: \[ 0.5 \, \text{mol O}_2 \times 22.4 \, \text{L/mol} = 11.2 \, \text{L} \]