Which of the following equations demonstrates the Law of Conservation of Mass?
CH4+O2→CO2+HO CH+O2→CO2+H2O CH4+O2→CO2+H2O CH4+O2→C+2H2O
CH4+O2→CO2+H2O
The equation that demonstrates the Law of Conservation of Mass is CH4 + 2O2 → CO2 + 2H2O.
This equation shows that when methane (CH4) reacts with oxygen (O2), it yields carbon dioxide (CO2) and water (H2O). The coefficients in front of the reactants and products represent the number of molecules or atoms involved in the reaction. Since the number of atoms on both sides of the reaction is the same, the Law of Conservation of Mass is satisfied.
The Law of Conservation of Mass states that mass is neither created nor destroyed during a chemical reaction. This means that the total mass of the reactants should be equal to the total mass of the products.
To determine which equation demonstrates the Law of Conservation of Mass, we need to examine the number of atoms of each element on both sides of the equation.
Let's evaluate each equation:
1. CH4 + O2 → CO2 + HO
There is an imbalance in the hydrogen atom count since there are 4 hydrogen atoms on the left side and only 1 on the right side. This equation does not demonstrate the Law of Conservation of Mass.
2. CH + O2 → CO2 + H2O
Again, there is an imbalance in the hydrogen atom count, so this equation does not demonstrate the Law of Conservation of Mass either.
3. CH4 + O2 → CO2 + H2O
This equation appears to have balanced the hydrogen atom count, with 4 hydrogen atoms on both sides. To further confirm, let's calculate the total number of each element on both sides of the equation:
- Carbon (C): 1 on the left side, 1 on the right side
- Hydrogen (H): 4 on the left side, 4 on the right side
- Oxygen (O): 2 on the left side, 3 on the right side
There is an imbalance in the oxygen atom count since there are 2 oxygen atoms on the left side and 3 on the right side. This equation does not demonstrate the Law of Conservation of Mass.
4. CH4 + O2 → C + 2H2O
This equation has balanced the hydrogen atom count and also the carbon atom count:
- Carbon (C): 1 on the left side, 1 on the right side
- Hydrogen (H): 4 on the left side, 4 on the right side
- Oxygen (O): 2 on the left side, 4 on the right side
The total number of each element is equal on both sides of the equation. Therefore, equation 4, CH4 + O2 → C + 2H2O, demonstrates the Law of Conservation of Mass.