Question

The following questions refer to the equilibrium shown here:

4NH3(g) + 5O2(g) <-> 4NO(g) + 6H2O(g)
For a certain reaction at 25.0°C, the value of K is 1.2 × 10–3. At 50.0°C the value of K is 3.4 × 10–1. This means that the reaction is:
a. Never favorable
b. More information needed
c. Endothermic
d. Exothermic
e. None of the above

Answer 1

The value of K changes, affected by temperature

Endothermic (ΔH = +): temperature rises ⇒ K increases

Exothermic (ΔH = -): temperature increases ⇒ K decreases

From the data in the problem, the value of K increases in proportion to the temperature, then the reaction is said to be endothermic (C)