Question

Explain why it is not possible for you to carry out displacement reactions using the metal potassium.

Answer 1

Answer:

Displacement reactions involve a metal and a compound of a different metal. In a displacement reaction:

a more reactive metal will displace a less reactive metal from its compounds

Displacement reactions are easily seen when a salt of the less reactive metal is in the solution. During the reaction:

the more reactive metal gradually disappears as it forms a solution

the less reactive metal coats the surface of the more reactive metal

For example, magnesium is more reactive than copper. When a piece of magnesium is dipped into blue copper sulfate solution:

the blue colour fades as colourless magnesium sulfate solution forms

brown copper coats the surface of the magnesium

Explanation:

Here are the equations for the reaction:

magnesium + copper sulfate → magnesium sulfate + copper

Mg + CuSO4 → MgSO4 + Cu

No reaction is seen if you do things the other way round – in other words, if you put copper powder into magnesium sulfate solution. This is because copper is not reactive enough to displace magnesium from magnesium sulfate.