Express your answer with the appropriate units.

Question

Under certain circumstances, carbon dioxide, CO2(g), can be made to react with hydrogen gas, H2(g), to produce methane, CH4(g), and water vapor, H2O(g):

CO2(g)+4H2(g)→CH4(g)+2H2O(g)

How many moles of methane are produced when 25.1 moles of carbon dioxide gas react with excess hydrogen gas?

How many moles of hydrogen gas would be needed to react with excess carbon dioxide to produce 30.6 moles of water vapor?

Answer 1

For the first question, the molar ratio of carbon dioxide to methane is 1:1, so 25.1 mol of carbon dioxide gives you 25.1 mol methane.

The ratio of hydrogen gas to water vapor is 4:2, so to produce 30.6 mol water vapor, you would need 61.2 mol hydrogen gas.