Example: In the combustion of propane, how many moles of O2 are consumed when 10.0 mol of H2O is produced?

Answer 1

The balanced chemical equation for the combustion of propane (C3H8) is:

C3H8 + 5 O2 -> 3 CO2 + 4 H2O

From the equation, we can see that 5 moles of O2 are consumed for every mole of propane that is burned. So, to find out how many moles of O2 are consumed when 10.0 moles of H2O is produced, we can use the mole ratio of O2 to H2O.

5 moles O2 : 4 moles H2O

10.0 moles H2O x (5 moles O2 / 4 moles H2O) = 12.5 moles O2

Therefore, 12.5 moles of O2 are consumed when 10.0 moles of H2O is produced in the combustion of propane.