Answer:
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
Option D.
Explanation:
This is a combustion reaction, where a compound reacts with oxygen to produce CO₂ and water.
You have to look at the reactants and the products.
C₃H₈ + O₂ → CO₂ + H₂O
To balance you must have the same atoms of each elements in both sides.
Actually we have 3 C, 8 H and 2 O in reactant side and 1 C, 3 O and 2H in product side.
We can add 4 to water to have 8 H in product side to balance the H with reactants but we modified the amount of oxygens. Now, we have 4 O in water and 2 O from CO₂ (6 in total).
In reactant side, we have 3 C, therefore we add 3 to CO₂ and now, we have 3 C on both sides and 8 H in both sides, so, as in product side we have 10 O, 6 from CO₂ and 4 from water, we must add a 5 to balance in reactant side. The balance equation will be:
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
