A : Bond energy is equal to enthalpy of formation with negative sign.
R: Bond energy is energy required to dissociate 1 mole single bond.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion , then mark (1)
B. If both Assertion & Reason are true and the reason is not the correct explanation of the assertion, then mark (2)
C. If Assertion is true statement but Reason is false, then mark (3)
D. If both Assertion is true statement but Reason is false, then mark (3)

Answer

To analyze the given statements, we need to evaluate both the assertion (A) and the reason (R) separately.

### Step 1: Understand the Assertion (A)
The assertion states: "Bond energy is equal to enthalpy of formation with a negative sign."

- **Explanation**: Bond energy refers to the amount of energy required to break a bond between two atoms in a molecule, resulting in the formation of gaseous atoms. On the other hand, the enthalpy of formation is the change in enthalpy when one mole of a compound is formed from its elements in their standard states. The assertion suggests that these two concepts are equivalent, which is not accurate.

### Step 2: Understand the Reason (R)
The reason states: "Bond energy is energy required to dissociate 1 mole single bond."

- **Explanation**: Bond energy is indeed defined as the energy required to break one mole of bonds in a gaseous substance. However, it is not limited to single bonds; it can also apply to double and triple bonds. Therefore, while the reason is partially correct, it is misleading because it restricts bond energy to single bonds only.

### Step 3: Conclusion
Both the assertion and the reason are incorrect based on the definitions and concepts in thermodynamics.

- **Assertion (A)**: False
- **Reason (R)**: False

### Final Answer
Both assertion and reason are false.

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