An underground iron pipe in damp soil is to be protected from rusting. Which of the following techniques would NOT work?
Useful info: Fe2+(aq) + 2e- → Fe(s) Eo = -0.44 V.
Explain - answer -
(a) The iron pipe is electrically connected using a wire to a Mg rod. (Mg2+(aq) + 2e- → Mg(s) Eo = -2.37 V)
(b) The iron pipe is electrically connected to bar of Zn. (Zinc is a more active metal than iron.)
(c) The iron pipe is connected to the positive end of a battery and the negative end is connected to an iron bar.
(d) The iron pipe is painted with several coats of paint.
(e) The iron pipe is galvanized.