Combustion of Octane - Someone help me..?

Question

I am totally mixed up about moles. The question is How many moles of CO2 are produced when 2.09 mol of octane is burned?
The answer is 16.7moles of CO2 but how do we get that answer?

Answer 1

Octane has 8 atoms of carbon per molecule, so forms 8 molecules of CO2 per molecule of octane. The same is true for moles - 1 mole of octane forms 8 moles of CO2. So now you multiply 8 by 2.09 to get 16.72 moles of CO2.