Question

consider the chemical reaction below. c₃h₈ + 5o₂ → ? co₂ + 4h₂o how would the chemical reaction be completed according to the law of conservation of mass? a. place a coefficient of 2 before the co₂. b. place a coefficient of 3 before the co₂. c. place a coefficient of 5 before the co₂. d. place a coefficient of 6 before the co₂.

Explanation:

Step1: Count carbon atoms on reactant side

The reactant $C_3H_8$ has 3 carbon atoms.

Step2: Apply law of conservation of mass

According to the law of conservation of mass, the number of carbon atoms on the product side must equal the number on the reactant side. In $CO_2$, each molecule has 1 carbon atom. So, to have 3 carbon atoms on the product side, we need 3 $CO_2$ molecules.

Answer:

B. Place a coefficient of 3 before the $CO_2$.