Question

A chemical equation is shown.

_Fe+Cl₂-FeCl3

From left to right, which set of coefficients will make the equation obey the law of conservation of mass?

Ο Α.3,1,2

8.2.1.3

C.23.2

D.1.3.1

Answer 1

To balance the chemical equation \( \text{Fe} + \text{Cl}_2 \rightarrow \text{FeCl}_3 \), we need to ensure that the number of each type of atom is the same on both sides of the equation.

1. **Identify the number of atoms on each side:**
- Reactants:
- Fe: 1
- Cl: 2
- Products:
- Fe: 1
- Cl: 3

2. **Balance the chlorine atoms:**
To have 3 Cl atoms on the reactant side, we need 1.5 molecules of \( \text{Cl}_2 \) (since each \( \text{Cl}_2 \) contains 2 Cl). However, since we need whole numbers, we can multiply the entire equation by 2 to avoid the fraction:
\[
2\text{Fe} + \text{Cl}_2 \rightarrow 2\text{FeCl}_3
\]

3. **Now, the number of atoms would be:**
- Reactants:
- Fe: 2
- Cl: 2
- Products:
- Fe: 2
- Cl: 6 (since \( 2 \times 3 = 6 \))

Since this is not balanced yet, here’s the correct approach based on the options given:

### Checking options:
- **A. 3, 1, 2**: \( 3\text{Fe} + \text{Cl}_2 \rightarrow 2\text{FeCl}_3 \)
- Reactants: Fe - 3, Cl - 2
- Products: Fe - 2, Cl - 6 (not balanced)

- **B. 2, 1, 3**: \( 2\text{Fe} + \text{Cl}_2 \rightarrow 2\text{FeCl}_3 \)
- Reactants: Fe - 2, Cl - 2
- Products: Fe - 2, Cl - 6 (not balanced)

- **C. 2, 3, 2**: \( 2\text{Fe} + 3\text{Cl}_2 \rightarrow 2\text{FeCl}_3 \)
- Reactants: Fe - 2, Cl - 6
- Products: Fe - 2, Cl - 6 (balanced)

- **D. 1, 3, 1**: \( \text{Fe} + 3\text{Cl}_2 \rightarrow \text{FeCl}_3 \)
- Reactants: Fe - 1, Cl - 6 (not balanced)

The correct answer that balances the equation and obeys the law of conservation of mass, ensuring that there are equal numbers of each type of atom on reactants and products sides, is:

**C. 2, 3, 2**.