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

$∆G=(-92.2kJ)-748K(-0.1987kJ/K)=-92.2KJ$

$92.2kJ-(-138.6276kJ)=56.46kJ=56kJ$ (not spontaneous)

$∆G=(-92.2kJ)-278K(-0.1987kJ/K)=-92.2KJ$

92.2kJ-(-55.2386kJ)=56.46kJ=-36.93kJ=-37.0kj

(spontaneous)