Question

Which of the following is/are the limitations of Pourbaix diagrams?

(a) Rate of reaction is can’t be predicted

(b) It neglects the impurities of working conditions

(c) Stability of metallic species is predicted

(d) Rate of reaction is not predicted and it neglects the impurities of working conditions

This question was addressed to me in an international level competition.

This interesting question is from Modern Theory Principles in chapter Modern Theory Principles of Corrosion Engineering

Answer 1

Right option is (d) Rate of reaction is not predicted and it neglects the impurities of working conditions

Easy explanation: Limitations of Pourbaix diagrams:

i. Rate of reaction can’t be predicted

ii. It neglects the impurities of working conditions

iii. Alloying elements of alloys are also neglected.