Question

Can copper sulphate solution be stored in an iron vessel? Explain.

Answer 1

Higher the standard reduction potential (Eº) value, greater the tendency of the species to accept electrons and undergo reduction.

Cu²⁺+2e^-→Cu,    Eº = + 0.337 V ;  Fe²⁺ + 2e^- → Fe, Eº = - 0.440 V

Therefore, Cu²⁺ has a greater tendency to undergo reduction than Fe²⁺ or Fe can reduce (or displace) Cu²⁺ ions from its salt solution.

Fe_(s) +Cu²_(aq) ^→ Fe²_(aq) + Cu_(s)

Hence, copper sulphate solution cannot be stored in an iron vessel as the iron vessel dissolves forming Fe²⁺ ions and Cu²⁺ ions from copper sulphate solution forms Cu.