Which of the following is not balanced equation?

Options

A. `Ca(HO)_(2) + CO_(2) to CaCO_(3) + H_(2)O`
B. `Fe + CuSO_(4) to FeSO_(4) + Cu`
C. `Kc1O_(4) overset (Delta) (rarr) KC1 + 2O_(2)`
D. `Cu + 2HNO_(3) to Cu(NO_(3))_(2) + 2NO_(2) +H_(2)O`

Answer

To determine which of the following equations is not balanced, we will analyze each equation step by step.

### Step-by-Step Solution:

1. **Identify the Equations**: First, we need to look at the provided equations. Let's assume we have four equations to analyze.

2. **Check the First Equation**:
- **Equation**: Calcium hydroxide reaction.
- **Reactants**: 1 Calcium (Ca), 2 Hydroxide (OH) groups.
- **Products**: 1 Calcium (Ca), 2 Hydroxide (OH) groups.
- **Balance Check**:
- Ca: 1 on both sides
- O: 2 on both sides
- H: 2 on both sides
- **Conclusion**: This equation is balanced.

3. **Check the Second Equation**:
- **Equation**: Iron and copper reaction.
- **Reactants**: 1 Iron (Fe), 1 Copper (Cu), 1 Sulfur (S), 4 Oxygen (O).
- **Products**: 1 Iron (Fe), 1 Copper (Cu), 1 Sulfur (S), 4 Oxygen (O).
- **Balance Check**:
- Fe: 1 on both sides
- Cu: 1 on both sides
- S: 1 on both sides
- O: 4 on both sides
- **Conclusion**: This equation is balanced.

4. **Check the Third Equation**:
- **Equation**: Potassium chlorate decomposition.
- **Reactants**: 1 Potassium (K), 1 Chlorine (Cl), 4 Oxygen (O).
- **Products**: 1 Potassium (K), 1 Chlorine (Cl), 2 O2 (which equals 4 O).
- **Balance Check**:
- K: 1 on both sides
- Cl: 1 on both sides
- O: 4 on both sides
- **Conclusion**: This equation is balanced.

5. **Check the Fourth Equation**:
- **Equation**: Copper and nitric acid reaction.
- **Reactants**: 1 Copper (Cu), 2 Hydrogen (H), 2 Nitrogen (N), 6 Oxygen (O) (from 2 HNO3).
- **Products**: 1 Copper (Cu), 2 Nitrogen (N), 6 Oxygen (O) (from Cu(NO3)2 and 2 NO2 and 2 H2O).
- **Balance Check**:
- Cu: 1 on both sides
- H: 2 on both sides
- N: 2 in reactants, 4 in products (2 from Cu(NO3)2 and 2 from 2 NO2)
- O: 6 on both sides
- **Conclusion**: This equation is NOT balanced.

### Final Answer:
The fourth equation is not a balanced equation.

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