Final answer:
When a less reactive metal is placed into a metal salt solution, typically no reaction occurs because the less reactive metal will not displace the metal ions from the solution.
Step-by-step explanation:
When a less reactive metal is added to a solution of a metal salt, no reaction will typically occur because the less reactive metal does not easily lose electrons to reduce the metal cations in the solution. An example that illustrates the concept of reactivity involves placing a clean piece of copper metal in a solution of silver nitrate. Here, copper is more reactive than silver, so the silver ions are reduced to the silver metal on the copper surface, while copper ions enter into the solution, indicated by a blue color from the copper ions.
The reaction can be split into two half-reactions, one for the oxidation of copper, and the other for the reduction of silver. This demonstrates a single displacement reaction, where a more reactive metal displaces a less reactive metal from its compound. However, when a less reactive metal is used, it doesn't have the tendency to displace the metal ions from the solution; hence, no visible reaction occurs.