Question

So I had to calculate the Gibbs Free energy for all the reactions:

Ca(s)+CO2(g)+12O2(g)→CaCO3(s) = ΔG∘ = -734  kJ  

CaCO3(s)→CaO(s)+CO2(g) = 131  kJ

CO(g)+H2O(g)→H2(g)+CO2(g) = -28.6 KJ

but now I have to predict what lowering the temeprature will do to Gibbs Free Energy:
it will decrease with decreasing temp.

	ΔG∘ will increase with decreasing temperature.
	ΔG∘ will change slightly with decreasing temperature.

Answer 1

Ca(s)+CO2(g)+12O2(g)→CaCO3(s)    ΔG∘ = -734  kJ  

In the above reaction ΔG∘ = -ve, so energy is released from the reaction and it is observed that gaseous reactants are converted to solid products. Hence the teperature is decreased so the ΔG∘

CaCO3(s)→CaO(s)+CO2(g) = 131  kJ

In the above reaction ΔG∘ = +ve, so energy is required for the reaction and solid reactants are converted to solid and gas products. Hence the temperature is increased so the ΔG∘ also increases

CO(g)+H2O(g)→H2(g)+CO2(g) = -28.6 KJ

ΔG∘ will increase with decreasing temperature.