The equilibrium constant for a reaction `A+B hArr C+D` is `1xx10^(-2)` at `298 K` and is `2` at `273 K`. The chemical process resulting in the formation of `C` and `D` is

Options

A. Exothermic
B. Endothermic
C. Unpredictable
D. There is no relationship between `DeltaH` and `K`.

Explanation

To determine the nature of the chemical process resulting in the formation of products C and D from reactants A and B, we can analyze the given equilibrium constants at two different temperatures.

### Step-by-Step Solution:

1. **Identify the Reaction**:
The reaction is given as:
\[ A + B \rightleftharpoons C + D \]

2. **Equilibrium Constants at Different Temperatures**:
- At 298 K, the equilibrium constant \( K_{298} = 1 \times 10^{-2} \)
- At 273 K, the equilibrium constant \( K_{273} = 2 \)

3. **Analyze the Change in Equilibrium Constant**:
- The equilibrium constant decreases from 2 at 273 K to \( 1 \times 10^{-2} \) at 298 K.
- This indicates that as the temperature increases, the equilibrium constant decreases.

4. **Interpret the Change**:
- According to Le Chatelier's principle, if an increase in temperature causes the equilibrium constant to decrease, the reaction favors the reverse direction (the formation of reactants A and B).
- This suggests that the forward reaction (formation of C and D) is less favored at higher temperatures.

5. **Determine the Nature of the Reaction**:
- For a reaction where increasing temperature favors the reverse reaction, it is indicative of an exothermic process. In an exothermic reaction, heat is released, and increasing temperature shifts the equilibrium to the left (toward the reactants).

6. **Conclusion**:
- Therefore, the chemical process resulting in the formation of C and D is **exothermic**.