One gram-atom of graphite and one gram-atom of diamond were separately burnt to `CO_(2)` . The amount of heat liberated was `393.5KJ` and `305.4KJ` respectively. It is apparent that

Options

A. graphite has greater affinity for oxygen
B. diamond has greater affinity for oxygen
C. graphite is more stable than diamond
D. diamond is more stable than graphite

Explanation

To solve the problem, we need to analyze the combustion of graphite and diamond, and the heat released during these reactions. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the combustion process
When graphite and diamond are burned in oxygen, they both produce carbon dioxide (CO₂). The combustion reactions can be represented as follows:
- For graphite: C (graphite) + O₂ → CO₂ + heat
- For diamond: C (diamond) + O₂ → CO₂ + heat

### Step 2: Analyze the heat released
We are given the amount of heat liberated during the combustion of each form of carbon:
- Heat released by graphite = 393.5 kJ
- Heat released by diamond = 305.4 kJ

### Step 3: Compare the heat values
From the values provided, we can see that the heat released during the combustion of graphite (393.5 kJ) is greater than that released by diamond (305.4 kJ). This indicates that more energy is released when graphite is burned compared to diamond.

### Step 4: Draw conclusions about stability
In thermodynamics, the amount of heat released during a reaction can be related to the stability of the reactants. A higher amount of heat released indicates that the reactant (in this case, graphite) is less stable than the product (CO₂). Conversely, if less heat is released (as in the case of diamond), it suggests that the reactant (diamond) is more stable.

### Step 5: Final conclusion
Since diamond releases less heat upon combustion compared to graphite, we can conclude that diamond is more stable than graphite.

### Final Answer:
**Diamond is more stable than graphite.**

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