How many moles of oxygen will burn?

Question

In a particular reaction, 4.5 moles of heptane burn in the presence of oxygen.

 

C7H16 + 11O2 -> 7CO2 + 8H2O How many moles of oxygen will burn?

 

REACTANTS:

Carbon: 7

Hydrogen: 16

Oxygen:  22

 

PRODUCTS:
Carbon:  7

Hydrogen:  16

Oxygen:  22

I'd like to understand HOW to arrive at the answer, not the answer by itself please.

Answer 1

A mole is a count of molecules, not a count of atoms.

 

Answer 2

You have 4.5 moles of heptane.  You also know that for every 1 mole of heptane that burns, 11 moles of oxygen will burn.  So, 4.5 moles * 11= 49.5 moles of oxygen, or 50. if you are considering sig figs.