11. (i) Explain why Copper, though a good conductor of electricity, is a non-electrolyte.   12. (ii) Name the gas released at the cathode when acidulated water is electrolysed.   13. (iii) Explain why solid Sodium chloride does not allow electricity to pass through.   14. (v) Fill in the blanks:- (1) As we descend the electrochemical series containing cations, the tendency of the cations to get _______ (oxidized/reduced) at the cathode increases.   15. (2) The (higher/lower) _______ the concentration of an ion in a solution, the greater is the probability of its being discharged at its appropriate electrode.