Question

How to write a Balanced Equation for:
The combustion of octane with oxygen gas?

Answer 1

The products for combustion are always carbon dioxide and water when subject to air (oxygen) and heat.

Answer 2

and remember that oxygen is a diatomic element, so it's \(O_2\), not just O

Answer 3

the no. of moles CO2 produced is equal to the no of carbon atoms in a compound and the no. of moles of water produced are half the no. of hydrogen atoms in the compound.
you can then balance the no. of oxygen.