The following data was collected for the following reaction at equilibrium 
2 A (g) + 3 B (g)  ⇌ C (g)     
At 25 ^oC K is 5.2 x 10^-4 and at 50 ^oC K is 1.7 x 10^-7. Which of the following statements is true?
a) The reaction is exothermic.
b) The reaction is endothermic.
c) The enthalpy change, ΔH, is equal to zero.
d) Not enough information is given. 

• A. The reaction is exothermic.
• B. The reaction is endothermic.
• C. The enthalpy change, ΔH, is equal to zero.
• D. Not enough information is given.

Answer: (A)

Verified step by step guidance

1. Identify the given data: The equilibrium constant K at 25°C is 5.2 x 10^-4, and at 50°C, it is 1.7 x 10^-7.
2. Understand the relationship between temperature and the equilibrium constant: According to Le Chatelier's principle, if the equilibrium constant decreases with an increase in temperature, the reaction is exothermic. Conversely, if the equilibrium constant increases with an increase in temperature, the reaction is endothermic.
3. Analyze the change in the equilibrium constant: The equilibrium constant decreases from 5.2 x 10^-4 at 25°C to 1.7 x 10^-7 at 50°C.
4. Apply the concept: Since the equilibrium constant decreases with an increase in temperature, this indicates that the reaction is exothermic.
5. Conclude the analysis: Based on the change in the equilibrium constant with temperature, the correct statement is that the reaction is exothermic.