To show that silver is chemically less reactive than copper, a common experiment involves placing silver metal into a solution containing copper ions.
Demonstrating Reactivity Differences
The relative reactivity of metals can be determined by observing their ability to displace other metals from their salt solutions. A more reactive metal will displace a less reactive metal from its salt solution. This principle is based on the metal reactivity series.
The Reactivity Series
Metals are arranged in the reactivity series based on their tendency to lose electrons and form positive ions. Metals higher in the series are more reactive than those lower down. Copper and silver are both relatively low in the series, but their positions relative to each other dictate how they will react in displacement experiments.
The Experiment: Silver in Copper Sulphate
According to the reference provided, the key observation that demonstrates silver's lower reactivity compared to copper is:
There will be no reaction when silver is immersed in a copper sulphate solution.
This lack of reaction occurs because silver is below copper in the reactivity series. Silver metal (Ag) does not have the ability to displace copper ions (Cu²⁺) from a copper sulphate solution (CuSO₄(aq)).
Why No Reaction?
A displacement reaction, if it occurred, would look like this:
Ag(s) + CuSO₄(aq) → No reaction
This observation confirms that silver is less reactive than copper. If silver were more reactive, it would displace copper from the solution, resulting in silver sulphate and solid copper being deposited.
Conversely, if you placed copper metal in a silver nitrate solution, a reaction would occur because copper is more reactive than silver, displacing silver from the solution.
Practical Demonstration
Here's how you could set up this experiment:
- Obtain a sample of silver metal (e.g., a piece of silver wire or foil).
- Prepare a solution of copper sulphate by dissolving copper sulphate crystals in water. The solution will be blue.
- Carefully place the silver metal into the copper sulphate solution.
- Observe the silver metal and the solution over a period of time (e.g., a few minutes to an hour).
Expected Outcome:
| Metal Added | Solution | Observation | Conclusion |
|---|---|---|---|
| Silver (Ag) | Copper Sulphate (CuSO₄) | No visible change | Silver is less reactive than Copper |
This simple experiment visually shows that silver cannot 'take the place' of copper in the copper sulphate solution, proving its lower chemical reactivity.
This demonstrates that silver cannot displace copper from copper sulphate, it has lower reactivity than copper, as stated in the reference.
