Question 1

(a) Corrosion is described as extractive metallurgy in reverse, to what extent do you agree with this statement? Explain.

(b) what is the influence of environment on the corrosion of metals.

(c) Mention six effects of corrosion damage

Question 2

Compute the voltage at 25 ^o C of an electo-chemical cell consisting of pure lead immersed in a 5 x 10^-2  M solution of Pb²⁺   ions and pure tin in a 0.25 M solution of Sn ²⁺  ions. Take V^o Pb and V^o Sn as -0.126 and -0.136 respectively.

(b) Write the spontaneous electo-chemical reaction.

(c) Calculate the value of dG^o at standard temperature and pressure for the corrosion of iron, assuming a divalent reaction. Take E ^o for Fe  to be +0.44 V and F as 96494 C..