Question

for the process delta H for A to X = 50kj

Answer 1

Answer:

For a reaction to be endothermic we have ΔH>0

For the reaction to be spontaneous we have ΔG<0

Consider case 1

ΔH=-50kJ   ΔS=+100J/K=+0.1kJ/K at 400 K

According to Gibb's free energy we have

ΔG=ΔH-TΔS

    =-50kJ-400*0.1kJ

    =-90kJ

The reaction is spontaneous but exothermic.

Consider case 2

ΔH=-50kJ ΔS=-100J/K=0.1kJ/K at 400K

According to Gibb's free energy we have

ΔG=ΔH-TΔS

    =-50kJ-400*(-0.1)k.J

    =-10k.J

Consider case 3

ΔH=+50kJ  ΔS=+100 J/K =+0.1kJ/K  at 600 K

According to Gibb's free energy we have

ΔG=ΔH-TΔS

    =50kJ-600*(0.1)kJ

    =-10k J

Case  4

The reaction is non-spontaneous but endothermic

Case 5

The reaction is equilibrium

so case 3 satisfies the condition of spontaneous and endothermic reaction.