Question

Which of the following equations follows the Law of Conservation of Mass?

a) 3H₂O → 3H₂ + O₂
b) C + 4H₂ → CH₄
c) 2Na + Cl₂ → 2NaCl
d) C₂H₄ + 3O₂ → 2CO₂ + 2H₂O

Answer 1

Equations c) 2Na + Cl2 → 2NaCl and d) C2H4 + 3O2 → 2CO2 + 2H2O are the only equations that follow the Law of Conservation of Mass as they have an equal number of each type of atom on both sides.

Step-by-step explanation:

To determine which of the given equations follows the Law of Conservation of Mass, we must check that the number of atoms of each element is the same on both sides of the equation. The Law of Conservation of Mass states that mass is neither created nor destroyed in a chemical reaction.

1. Equation a) 3H2O → 3H2 + O2 is not balanced because there are 6 hydrogen atoms and 3 oxygen atoms on the left side, but there are 6 hydrogen atoms and only 2 oxygen atoms on the right.
2. Equation b) C + 4H2 → CH4 is also not balanced because there are 1 carbon atom and 8 hydrogen atoms on the left side, but only 1 carbon atom and 4 hydrogen atoms on the right.
3. Equation c) 2Na + Cl2 → 2NaCl is balanced with 2 sodium atoms and 2 chlorine atoms on both sides.
4. Equation d) C2H4 + 3O2 → 2CO2 + 2H2O is balanced with 2 carbon atoms, 4 hydrogen atoms, and 6 oxygen atoms on both sides.

Thus, the equations that follow the Law of Conservation of Mass are c) 2Na + Cl2 → 2NaCl and d) C2H4 + 3O2 → 2CO2 + 2H2O.