To determine whether the chemical equation Zn + HCl → ZnCl₂ + H₂ is balanced, we need to count the number of atoms of each element on both sides of the equation.
Unbalanced Equation:
Zn + HCl → ZnCl₂ + H₂
Step-by-Step Analysis:
1. Count the atoms on the reactants side:
- Zn: 1
- H: 1
- Cl: 1
2. Count the atoms on the products side:
- Zn: 1
- H: 2
- Cl: 2
Comparison:
- Zinc (Zn) atoms are already balanced (1 on both sides).
- Hydrogen (H) atoms are not balanced (1 on the reactant side, 2 on the product side).
- Chlorine (Cl) atoms are not balanced (1 on the reactant side, 2 on the product side).
Balancing the Equation:
To balance the number of H and Cl atoms, we need to ensure there are equal numbers of these atoms on both sides of the equation. We can achieve this by placing a coefficient of 2 in front of HCl on the reactants side.
Balanced Equation:
Zn + 2HCl → ZnCl₂ + H₂
Balanced Atoms Count:
- Reactants:
- Zn: 1
- H: 2 (since we have 2 HCl molecules, each contributing 1 H atom)
- Cl: 2 (since we have 2 HCl molecules, each contributing 1 Cl atom)
- Products:
- Zn: 1
- H: 2 (from H₂)
- Cl: 2 (from ZnCl₂)
Now the equation is balanced with:
- Zinc (Zn): 1 atom on both sides
- Hydrogen (H): 2 atoms on both sides
- Chlorine (Cl): 2 atoms on both sides
Identification of Reactants and Products:
- Reactants: Zn (Zinc) and 2HCl (Hydrochloric acid)
- Products: ZnCl₂ (Zinc chloride) and H₂ (Hydrogen gas)
Type of Reaction:
The reaction Zn + 2HCl → ZnCl₂ + H₂ is classified as a combination reaction. In this type of reaction, different substances combine to form new compounds.
So, the balanced form of the equation is:
Zn + 2HCl → ZnCl₂ + H₂
