To balance the chemical equation:
Unbalanced reaction: \[ \text{HgCl}_2 + \text{Al} \rightarrow \text{AlCl}_3 + \text{Hg} \]
Step 1: Count the atoms of each element on both sides.
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Reactants:
- Hg: 1
- Cl: 2
- Al: 1
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Products:
- Al: 1
- Cl: 3
- Hg: 1
Step 2: Balance the chlorine atoms.
To balance the Cl atoms, we need to change the coefficient of \(\text{AlCl}_3\) to 2:
Updated equation: \[ \text{HgCl}_2 + \text{Al} \rightarrow 2\text{AlCl}_3 + \text{Hg} \]
This gives us:
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Reactants:
- Hg: 1
- Cl: 2
- Al: 1
-
Products:
- Al: 2
- Cl: 6 (2 x 3 from \(\text{AlCl}_3\))
- Hg: 1
Step 3: Balance the aluminum and mercury atoms.
Now, let’s balance the aluminum by placing a coefficient of 2 in front of Al in the reactants:
Balanced equation: \[ \text{HgCl}_2 + 2\text{Al} \rightarrow 2\text{AlCl}_3 + \text{Hg} \]
Final counts:
-
Reactants:
- Hg: 1
- Cl: 2
- Al: 2
-
Products:
- Al: 2
- Cl: 6
- Hg: 1
Now we can balance the Cl by putting a coefficient of 3 before \(\text{Hg}\):
Final balanced equation: \[ \text{HgCl}_2 + 3\text{Al} \rightarrow 2\text{AlCl}_3 + 3\text{Hg} \]
Thus, the balanced coefficients are:
- HgCl2: 1
- Al: 3
- AlCl3: 2
- Hg: 3
So, the final coefficients are: 1, 3, 2, 3