Answer to Question #269477 in General Chemistry for ela

Question

Exercise. Given the equation, calcite the standard free energy change. Answer what is being asked.

1. 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?

2. The enthalpy and entropy change of a reaction are -3.9 kJ/mole and +56.6 J/mole K respectively at 25o C. What is the free energy change in kJ/mole? Is this reaction always spontaneous, never spontaneous or does it depend on the temperature?

Answer 1

∆G = ∆H - ∆TS

∆H = -3.9KJ/mol

T = 25 + 273 = 298K

∆S = 56.6J/mol = 0.056KJ/mol

∆G = -3.9 - 298(0.056)

= -3.9 - 16.688

= -20.588KJ/mol

The reaction is spontaneous