Using Ellingham diagram answer the following questions:

a) Calculate the deltaG, at 1100C, of the following reaction: Cr2O3 + 2Al ---> 2Cr + Al2O3 and state whether the reaction is spontaneous.

b) Using a furnace with a controlled atmosphere of hydrogen of 99.99% purity (consider H2/H2O ~ 10000): what would be the minimum temperature required to reduce TiO2 and NiO and obtain Ti and Ni. Which of these oxides is more stable?

c) Using a vacuum furnace, what would be the O2 partial pressure to reduce V2O3 and Cu2O to obtain V and Cu at 1200C? Which of these oxides is most stable at this temperature?