Answer to Question #268279 in General Chemistry for ceejay

Question

N2(g)+3H2(g) --->2NH3(g)

If ΔH = -92.2kJ and ΔS= -0.1987kJ/K, what is ΔG for the reaction at 475°C and at 5°C? Provide the answer in kJ. In each case, is the reaction spontaneous?

Answer 1

ΔG = (-92.2 kJ) – 748K(-0.1987 kJ/K) = -92.2 kJ – (-148.6276 kJ) = 56kJ (not spontaneous) ΔG = (-92.2 kJ) – 278K(-0.1987 kJ/K) = -92.2 kJ – (-55.2386 kJ) = -37.0kJ (spontaneous)