Question

Use the table to answer the question.

Reaction CH4 + 4Cl2 → CCl4 + 4HCl
Reactants Products
Bonds Present
4 H–C

4 Cl–Cl

4 C–Cl

4 H–Cl

Energy of Bonds Broken (Reactants) / Formed (Products)

4 × 411 kJ/mol

4 × 242 kJ/mol

4 × 327 kJ/mol

4 × 427 kJ/mol

Which statement about the change in bond energy of this reaction is correct?

Responses

The reaction is endothermic because the total bond energy of the reactants is greater than the total bond energy of the products.
The reaction is endothermic because the total bond energy of the reactants is greater than the total bond energy of the products. - no response given

The reaction is endothermic because the energy of each bond in the reactants is less than the energy of a bond in the products.
The reaction is endothermic because the energy of each bond in the reactants is less than the energy of a bond in the products. - no response given

The reaction is exothermic because the total bond energy of the reactants is less than the total bond energy of the products.
The reaction is exothermic because the total bond energy of the reactants is less than the total bond energy of the products. - no response given

The reaction is exothermic because the energy of each bond in the reactants is greater than the energy of a bond in the products.
The reaction is exothermic because the energy of each bond in the reactants is greater than the energy of a bond in the products. - no response given
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Answer 1

Let's analyze the reaction and the associated bond energies provided to determine if the reaction is endothermic or exothermic.

The reaction is:
\[ \text{CH}_4 + 4\text{Cl}_2 \rightarrow \text{CCl}_4 + 4\text{HCl} \]

### Bonds Present:
- **Reactants:**
- 4 H-C bonds
- 4 Cl-Cl bonds

- **Products:**
- 4 C-Cl bonds
- 4 H-Cl bonds

### Energy of Bonds:
- Energy of breaking bonds in reactants:
- For 4 H-C bonds: \( 4 \times 411 \, \text{kJ/mol} = 1644 \, \text{kJ/mol} \)
- For 4 Cl-Cl bonds: \( 4 \times 242 \, \text{kJ/mol} = 968 \, \text{kJ/mol} \)

Total energy of bonds broken (reactants):
\[
1644 \, \text{kJ/mol} + 968 \, \text{kJ/mol} = 2612 \, \text{kJ/mol}
\]

- Energy of forming bonds in products:
- For 4 C-Cl bonds: \( 4 \times 327 \, \text{kJ/mol} = 1308 \, \text{kJ/mol} \)
- For 4 H-Cl bonds: \( 4 \times 427 \, \text{kJ/mol} = 1708 \, \text{kJ/mol} \)

Total energy of bonds formed (products):
\[
1308 \, \text{kJ/mol} + 1708 \, \text{kJ/mol} = 3016 \, \text{kJ/mol}
\]

### Change in Bond Energy:
- Total energy of bonds broken (reactants) = 2612 kJ/mol
- Total energy of bonds formed (products) = 3016 kJ/mol

### Calculation of ΔH:
To find whether the reaction is endothermic or exothermic, we use the formula:
\[
\Delta H = \text{Energy of bonds broken} - \text{Energy of bonds formed}
\]
\[
\Delta H = 2612 \, \text{kJ/mol} - 3016 \, \text{kJ/mol} = -404 \, \text{kJ/mol}
\]

Since ΔH is negative, the reaction is **exothermic**.

### Conclusion:
The correct answer is:
**The reaction is exothermic because the total bond energy of the reactants is less than the total bond energy of the products.**