Answer:
See explanation
Step-by-step explanation:
1) The reaction of magnesium with oxygen is;
Mg(s) + O2(g) -----> MgO2(s)
The oxidizing agent is the reactant whose oxidation number decreases from left to right in the reaction equation. The oxidation state of oxygen decreased from zero to -2 hence oxygen is the oxidizing agent in the reaction.
2) The advantages of fuel cell includes;
i) it is a clean source of energy
ii) Fuel cells operate quietly and do not constitute noise pollution
One disadvantage of the fuel cell is that its operation is costly.
3) Electrolytic and voltaic cell are similar because they are both electrochemical cells and involve a transfer of electrons between two electrodes.
Electrolytic cells do not operate spontaneously while voltaic cells operate spontaneously. In the volatic cell the anode is negatively charged while the cathode is positively charged. In the electrolytic cell, the anode is positively charged while the cathode is negatively charged.