In the reaction for the transition of carbon in the diamond form to carbon in the graphite form, `Delta H` is `-453.5` cal. This points out that

Options

A. Graphite is chemically different from diamond
B. Graphite is as stable as diamond
C. Graphite is more stable than diamond
D. Diamond is more stable than graphite

Answer

To solve the problem regarding the transition of carbon from diamond to graphite and the implications of the given ΔH value, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Reaction**: The reaction in question is the transition of carbon from its diamond form (C_diamond) to its graphite form (C_graphite).

2. **Identify ΔH Value**: We are given that ΔH = -453.5 cal for this reaction. The negative sign indicates that the reaction releases heat.

3. **Determine the Type of Reaction**: Since ΔH is negative, this indicates that the reaction is exothermic. In an exothermic reaction, energy is released to the surroundings.

4. **Analyze Stability**: In thermodynamics, if a reaction is exothermic, it suggests that the products (in this case, graphite) are more stable than the reactants (diamond). This is because the system tends to move towards a lower energy state.

5. **Conclude the Stability Comparison**: Since graphite is the product of this reaction and it is more stable than diamond (due to the exothermic nature of the reaction), we can conclude that graphite is more stable than diamond.

6. **Evaluate the Statements**: Based on the stability comparison, we can evaluate the provided statements regarding the stability of graphite and diamond. The correct conclusion is that graphite is more stable than diamond.

### Final Conclusion:
The transition of carbon from diamond to graphite is exothermic (ΔH = -453.5 cal), indicating that graphite is more stable than diamond.