(Solved):   3 Use the Ellingham diagram in Figure 1 below to answer the following questions: a) The sl ...

 

3 Use the Ellingham diagram in Figure 1 below to answer the following questions: a) The slope of the line for the reaction \[ \mathrm{C}(\mathrm{s})+\mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{CO}_{2}(\mathrm{~g}) \] is zero. What is the disadvantage of this trend in metal extraction processes? (5 marks) b) Indicate the temperature at which the following reactions are at equilibrium (5 marks) \[ \begin{array}{l} \mathrm{Cu}_{2} \mathrm{O}+\mathrm{C} \rightarrow 2 \mathrm{Cu}+\mathrm{CO} \\ \mathrm{SiO}_{2}+\mathrm{C} \rightarrow \mathrm{Si}+\mathrm{CO} \end{array} \] c) State, giving reasons, whether or not carbon can reduce magnesium oxide \( (\mathrm{MgO}) \) at \( 1000^{\circ} \mathrm{C} \) \( (5 \) marks) d) Prove that the slope of the \( \Delta G \) versus \( T \) curve is similar for magnesium \( (\mathrm{Mg}) \) and aluminium \( (\mathrm{Al}) \) at temperatures below \( 800^{\circ} \mathrm{C} \) (5 marks)