Four successive members of the first series of the transition metals are listed below. For which one of them does the standard potential (E°M²/M) value have a positive sign?
Ni(Z=28)
Cu(Z=29)
Co(Z=27)
Fe(Z=26)
Solution:
In the electrochemical series, Cu is below hydrogen. Hence, it has a positive value of standard reduction potential (E°M²/M). The standard reduction potentials are given below.