Question

How many moles of carbon dioxide gas can be produced when 12.8 moles of benzene (C6H6) react with excess oxygen?

Unbalanced equation: C6H6 + O2 → CO2 + H2O

Show, or explain, all of your work along with the final answer.

Answer 1

try to balance your equation first
the number of atoms in the reactants must match the number of atoms in the product

Answer 2

C6H6 + 15/2 O2 → 6CO2 + 3H2O
first, balance your equation. Since oxygen is excess, the limiting reactant is the benzene. So no need to worry about the oxygen. You can ignore it if only if its excess. Next, find the mole ratio between benzene and carbon dioxide.

In this case, 1 mole of benzene produce 6 moles of carbon dioxide.
Subsequently, 12.8 mole of benzene will produce 6 times more of carbon dioxide.