2C8H18+25O2→ 18H2+16CO2+energy

Answer 1

So, what exactly is your question?

It isn't the correct equation, as you have H₂ as a product and it should be H₂O.

2C₈H₁₈ + 25O₂ ==> 16CO₂ + 18H₂O ... correctly balanced equation

If the question is whether it is endothermic or exothermic, the answer would be exothermic as heat is released as a product.

Still not sure what you are asking.