Final answer:
The minimum number of moles of O2 required for the complete combustion of 1 mole of propane and 2 moles of butane is 18 moles, derived from balancing the chemical equations for the combustion of each hydrocarbon.
Step-by-step explanation:
To find the minimum number of moles of O2 required for the complete combustion of 1 mole of propane (C3H8) and 2 moles of butane (C4H10), we need to write and balance the chemical equations for the combustion of each hydrocarbon.
The balanced equation for the combustion of propane is:
C3H8 + 5O2 → 3CO2 + 4H2O
This indicates that for every mole of propane, 5 moles of O2 are required for complete combustion.
The balanced equation for the combustion of butane is:
C4H10 + ⅛₇O2 → 4CO2 + 5H2O
This indicates that for every mole of butane, ⅛₇ (∼6.5) moles of O2 are required for complete combustion. Therefore, for 2 moles of butane, we need 2 x 6.5 = 13 moles of O2.
Altogether, for the complete combustion of 1 mole of propane and 2 moles of butane, the total moles of O2 required are:
1 mole of C3H8 x 5 moles of O2/mole of C3H8 + 2 moles of C4H10 x 6.5 moles of O2/mole of C4H10
5 moles of O2 + 13 moles of O2 = 18 moles of O2
Therefore, the minimum number of moles of O2 required is 18 moles.