To balance the given chemical reaction, let's analyze it step by step.
The unbalanced equation is:
[tex]\[ \square \text{Zn} + \square \text{HCl} \rightarrow \square \text{ZnCl}_2 + \square \text{H}_2 \][/tex]
Step 1: Identify the reactants and products along with their chemical formulas.
- Reactants: Zn and HCl
- Products: ZnCl₂ and H₂
Step 2: Write down the number of atoms of each element on both sides of the equation.
Unbalanced:
- Zn: 1 Zn atom on the reactant side, 1 Zn atom on the product side
- H: 1 H atom from HCl on the reactant side, 2 H atoms (H₂) on the product side
- Cl: 1 Cl atom from HCl on the reactant side, 2 Cl atoms (ZnCl₂) on the product side
Step 3: Balance each element one by one.
1. Balance Zinc (Zn):
- Zinc is already balanced with 1 Zn atom on both sides.
[tex]\[\text{Zn} + \square \text{HCl} \rightarrow \text{ZnCl}_2 + \square \text{H}_2\][/tex]
2. Balance Chlorine (Cl):
- There are 2 Cl atoms in ZnCl₂. Therefore, we need 2 HCl molecules to provide 2 Cl atoms.
[tex]\[ \text{Zn} + 2 \text{HCl} \rightarrow \text{ZnCl}_2 + \square \text{H}_2\][/tex]
3. Balance Hydrogen (H):
- Now, we have 2 H atoms from 2 HCl molecules on the reactant side. These correspond to the 2 H atoms in H₂ on the product side.
[tex]\[ \text{Zn} + 2 \text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2\][/tex]
Step 4: Verify the balance:
- Zinc (Zn): 1 atom on both sides
- Hydrogen (H): 2 atoms on both sides
- Chlorine (Cl): 2 atoms on both sides
Final balanced equation:
[tex]\[ \text{Zn} + 2 \text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2 \][/tex]
Therefore, the coefficients needed to balance the equation are:
[tex]\[ 1 \; \text{Zn}, \; 2 \; \text{HCl}, \; 1 \; \text{ZnCl}_2, \; 1 \; \text{H}_2 \][/tex]
So the answer is:
[tex]\[ (1, 2, 1, 1) \][/tex]
Therefore, the balanced equation is:
[tex]\[ \text{Zn} + 2 \text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2 \][/tex]
This matches the coefficients (1, 2, 1, 1) confirming that the equation is correctly balanced.
