How do Metals react with Solutions of other Metal Salts ?
Reactive metals can displace less reactive metals from their compounds in solution or molten form.
All metals are not equally reactive. We checked the reactivity of various metals with oxygen, water and acids. But all metals do not react with these reagents.
So we were not able to put all the metal samples we had collected in decreasing order of their reactivity. Displacement reactions give better evidence about the reactivity of metals. It is simple and easy if metal A displaces metal B from its solution, it is more reactive than B.
Metal A + Salt solution of B → Salt solution of A + Metal B