1. a) Calculate the value of standard molar Gibbs free energy change of chemical reaction at 298 K using the data given below:

Is the chemical reaction exothermic reaction or endothermic? WHY?

4/3Al(s)+O₂(g)2/3Al₂O₃ (g) at 298K

b) Calculate the enthalpy and entropy of chemical reaction at 1000K. Leave calculations in the integral form after putting cp values. Organize them as we do it in the class.

4/3Al(l)+O₂(g)2/3Al₂O₃ (g) at 1273K

DATA:

DH Al (sl)=10500 joules at 932K,

Standard molar enthalpy formation and entropy at 298K:

H^o_fAl₂O₃= -1674000joules,

S^oAl(s)=28.3 J/K, S^o Al₂O₃=59.6 J/K, S^oO₂=205 J/K

1. (30) When SO_3(g) is decomposed at the constant pressure P and T= 1000K, the partial pressure of O₂ in the equilibrium gas is 0.05 atm.
2. What is the pressure P?
3. If the pressure of this equilibrated gas is increased to 1.5 atm, to what value must be the temperature to decreased to produce a gas mixture in which pO₂= 0.05 atm?

G^o= - 94600+89.37 T for SO₂(g)+1/2O₂(g)= SO₃(g)