The principles of electrochemistry are applied in fuel cells, corrosion and metal/mineral processing, (a) The following questions are based on a fuel cell: (1) What is a fuel cell? (ii) What type of electrochemical cell is a fuel cell? (iii) For a fuel cell, write the balanced half reactions at the cathode and the anode as well as the overall balanced reaction including state symbols. (b) Consider the following diagram of a drop of water on a piece of iron that is being protected from corrosion by magnesium: Water containing dissolved oxygen Iron Magnesium (1) Give the name of the specific technique that is used to protect iron from corrosion illustrated in the diagram (ii) Briefly explain the principle behind the type of technique that is used to protect iron from corrosion mentioned in part (i).