(i) The free energy of the formation of a metal oxide to be fabricated into pinion gear of an automotive component varies between 1 to 5 kJ/mole in a temperature range -40C to 40C. The component will be used under dry atmospheric conditions when the service temperature varies between 0C to 35C. Predict whether it is advisable to protect the component from corrosion by surface coating. Justify your answer.

(ii) A pressure vessel made of an iron (Fe) base alloy is designed to operate in an acid environment. It is connected to a magnesium (Mg) base alloy component. Predict which one of the two components will corrode from a thermodynamic point of view. State clearly your predicted assumption.

(iii) Fe is protected when connected or coupled to Zn. Justify the validity of the statement by constructing E- log I kinetic diagrams for both Fe and Zn respectively.