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?
A. 3, 1, 2
B. 2, 1, 3
C. 2, 3, 2
D. 1, 3 ,1

Answer 1

To balance the chemical equation \(__Fe + __Cl_2 → __FeCl_3\) according to the law of conservation of mass, we need to ensure that the number of atoms of each element on the reactant side is equal to the number of atoms on the product side.

Let's analyze each option given:

1. **Option A: 3, 1, 2**
- The equation would be: \(3Fe + 1Cl_2 → 2FeCl_3\)
- Reactants: 3 Fe, 2 Cl (from Cl2)
- Products: 2 Fe, 6 Cl (from 2FeCl3)
- This does not balance.

2. **Option B: 2, 1, 3**
- The equation would be: \(2Fe + 1Cl_2 → 3FeCl_3\)
- Reactants: 2 Fe, 2 Cl (from Cl2)
- Products: 3 Fe, 9 Cl (from 3FeCl3)
- This does not balance.

3. **Option C: 2, 3, 2**
- The equation would be: \(2Fe + 3Cl_2 → 2FeCl_3\)
- Reactants: 2 Fe, 6 Cl (from 3Cl2)
- Products: 2 Fe, 6 Cl (from 2FeCl3)
- This balances.

4. **Option D: 1, 3, 1**
- The equation would be: \(1Fe + 3Cl_2 → 1FeCl_3\)
- Reactants: 1 Fe, 6 Cl (from 3Cl2)
- Products: 1 Fe, 3 Cl (from 1FeCl3)
- This does not balance.

The correct answer is **C. 2, 3, 2**, which correctly conserves mass according to the law of conservation of mass.