Question

Arrange the following metals in which they displace each other from the solutions of their salts in decreasing order. Al, Cu, Fe, Mg and Zn.

$\lbrack{E^{o}}_{Al^{3 +}/Al} = - 1.66V,{E^{o}}_{Cu^{2 +}/Cu} = + 0.34V,$

${E^{o}}_{Fe^{2 +}/Fe} = - 0.44V,{E^{o}}_{Mg^{2 +}/Mg} = - 2.36V$ and

${E^{o}}_{Zn^{2 +}/Zn} = - 0.76V\rbrack$

• A. Cu, Fe, Zn, Al, Mg
• B. Fe, Zn, Cu, Al, Mg
• C. Mg, Cu, Fe, Zn, Al
• D. Mg, Al, Zn, Fe, Cu

Answer 1

Answer: (D)

Mg, Al, Zn, Fe, Cu

Answer 2

: Since a metal with lower electrode potential is a stronger reducing agent, Mg can displace all the given metals, Al can displace all metals except Mg. Zn can displace all metals except Mg and Al. Fe can displace only Cu. The order in which they can displace each other from their salt solutions is Mg, Al, Zn, Fe, Cu.