Final Answer:
The coefficient for O₂ after balancing the equation C₃H₈ + 5O₂ → 3CO₂ + 4H₂O is 5 (Option 1).
Step-by-step explanation:
Balancing a chemical equation involves adjusting coefficients to ensure that the same number of each type of atom is present on both sides of the equation. Start by balancing carbon and hydrogen atoms, then balance oxygen atoms last. In this case, the balanced equation is C₃H₈ + 5O₂ → 3CO₂ + 4H₂O. The coefficient of O₂ is 5, ensuring that there are equal numbers of oxygen atoms on both sides of the equation. This balance preserves the law of conservation of mass, indicating that the number of each type of atom remains constant before and after the reaction.
Option 1 is the answer.