3.1 Arrange the following metals in the order in which they displace each other from the solution of their salts.

Al, Cu, Fe, Mg and Zn.

A metal of stronger reducing power displaces another metal of weaker reducing power from its solution of salt.

The order of the increasing reducing power of the given metal is Cu < Fe < Zn < Al < Mg
 
The following is the order in which the given metals displace each other from the solution of their salts.
Mg, Al, Zn, Fe, Cu