In a reversible reaction `K_(c)gtK_(p)andDeltaH=+40k`Cal. The product will be obtained in less amount at :-

Options

A. High pressure , high temperature
B. Low pressure , low temperature
C. High pressure , low temperature
D. Low pressure , high temperature

Answer

To solve the question, we need to analyze the given information about the reversible reaction and the conditions under which the product will be obtained in lesser amounts.

### Step-by-Step Solution:

1. **Understanding the Relationship Between Kc and Kp**:
- The relationship between Kc (equilibrium constant in terms of concentration) and Kp (equilibrium constant in terms of pressure) is given by the equation:
\[ K_p = K_c \cdot R T^{\Delta N} \]
- Here, \( \Delta N \) is the change in the number of moles of gas, calculated as:
\[ \Delta N = \text{(moles of gaseous products)} - \text{(moles of gaseous reactants)} \]

2. **Analyzing the Given Condition**:
- We are given that \( K_c > K_p \). This implies that:
\[ \Delta N < 0 \]
- This means that there are more moles of reactants than products in the equilibrium state, indicating that the products are formed in lesser amounts.

3. **Considering the Enthalpy Change**:
- The problem states that \( \Delta H = +40 \, \text{kcal} \), which indicates that the reaction is endothermic. In an endothermic reaction, heat is absorbed, and increasing the temperature favors the formation of products.

4. **Applying Le Chatelier's Principle**:
- According to Le Chatelier's principle, if we increase the pressure of a system at equilibrium, the system will shift in the direction that reduces the pressure. In this case, since \( \Delta N < 0 \), increasing the pressure will favor the side with fewer moles of gas, which is the reactants.

5. **Conclusion**:
- Therefore, to obtain the product in lesser amounts, we need to maintain high pressure (which favors the reactants) and high temperature (which favors product formation due to the endothermic nature of the reaction).
- Thus, the correct answer is that the product will be obtained in less amount at **high pressure and high temperature**.

### Final Answer:
The product will be obtained in less amount at **high pressure and high temperature**.