Answer:
Step-by-step explanation:
1) For every 2 moles of methane consumed, 8 moles of carbon dioxide are produced. This means that if 4 moles of methane are consumed, the reaction can occur twice, meaning 8(2)=16 moles of carbon dioxide will be produced.
2) For every 2 moles of methane consumed, 10 moles of water are produced. This means that the reaction can occur twice, and hence 10(2)=20 moles of water will be produced.
3) For every 10 moles of water produced, 13 moles of oxygen gas are consumed. This means that if we want 126 moles of water, we need the reaction to occur 12.6 times, and thus 13(12.6)=163.8 moles of oxygen gas will be consumed.