Q. Four successive members of the first series of the transition metals are listed below. For which one of them the standard potential E°(M²⁺/M) value has a positive sign?
A) Co (Z = 27)
B) Ni (Z = 28)
C) Cu (Z = 29)
D) Fe (Z = 26)
Explanation
[Solution from source] Copper is the only one of these with a positive E°(M²⁺/M), about +0.34 V, because its high atomisation enthalpy and low hydration enthalpy are not compensated. Fe, Co and Ni all have negative values. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.