Neco 2017 Chemistry Question 41

Metal X forms the oxide XO. The standard enthalpy of formation of XO is \(-350\ \text{kJ mol}^{-1}\) and the standard entropy of formation is \(-120\ \text{J mol}^{-1}\text{K}^{-1}\). (a) Calculate the temperature at which the oxide would start to decompose spontaneously (i.e., \(\Delta G^{\circ}=0\)). (b) The waste treatment plant operates at \(1200\ \text{K}\). Will the oxide decompose at this temperature? (c) Considering the reaction \(\text{XO}+\text{C}\rightarrow\text{X}+\text{CO}\) and that the standard Gibbs free energy for \(\text{C}+\frac{1}{2}\text{O}_2\rightarrow\text{CO}\) at \(1200\ \text{K}\) is \(-110\ \text{kJ mol}^{-1}\), state whether carbon can reduce the oxide at the plant temperature.