If 2.79 mol of C5H12 reacts with excess O2, how many moles of CO2 will be produced by the following combustion reaction? C5H12+8O2⟶6H2O+5CO2

Answer 1

First step is to identify the problem. It is a combustion with c5h13 as the limiting reactant. OK. Now that is identified, you have to solve the problem in finding the amount of CO2. This is where the mole ratio and stoichiometry comes into play. For every 1 mole of C5H12 that you burn, it produces 5 CO2. It can be written as this :

5 mole CO2

——————

1 mole C5H12

Now that you know the rate at which CO2 is produced, what happens if you have 2.79 moles of C5H12? Using stoichiometry there is an answer. So I have

2.79 mol C5H12

However, it needs to be converted to CO2. So you use the mole ratio between C5H12 and CO2

5 mole CO2

2.79 mol C5H12 × —————— = 13.95 mole CO2

1 mole C5H12

I put the C5H12 on the bottom so the units can divide by itself any be left with units for CO2 only. As a result, you are left with 13.95 moles of CO2