Question

\(N_{2}+3H_{2}\rightleftharpoons2NH_{3}\) favours the following conditions

• A. Low Pressure. High Temperature
• B. High Pressure. Low Temperature
• C. Low Pressure. Low Temperature
• D. High Pressure. High Temperature

Hint:

Logic Tip: 4 gas molecules shrink into 2, so squeeze them with High Pressure! The reaction generates heat, so cool it down with Low Temperature to keep the reaction moving forward!

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Le Chatelier's Principle states that if a system at equilibrium is disturbed, the system will shift to counteract the disturbance. This reaction (Haber Process) is exothermic ($\Delta H<0$) and involves a decrease in volume (4 moles of gas $\rightarrow$ 2 moles of gas).
Step 2: Key Formula or Approach:
1. Pressure: Increasing pressure shifts equilibrium toward the side with fewer gas moles. 2. Temperature: Decreasing temperature shifts equilibrium toward the exothermic direction.
Step 3: Detailed Explanation:

Pressure: There are 4 moles on the left and 2 on the right. High pressure favors the forward reaction.
Temperature: Since the reaction releases heat, low temperature favors the forward reaction. However, in industrial practice, a "compromise temperature" (around 450°C) is used because the reaction rate is too slow at very low temperatures.

Step 4: Final Answer:
The reaction favors High Pressure and Low Temperature.