Who pushes whom out

The idea

A more reactive metal displaces a less reactive metal from its compounds in solution or molten form, so if metal A displaces metal B from its salt solution, A is more reactive than B.

A metal in a salt solution

Metal A is put in a solution of a salt of metal B.

What might happen?

• A may take B's place in the solution
• Nothing happens
• Both metals vanish

Displace the metal

Press Next step. A and B are examples.

Better evidence

Metals do not all react with oxygen, water or acids, so those tests cannot put every metal in order. Displacement reactions give better evidence. A more reactive metal displaces a less reactive one from its compounds, in solution or in the molten form. So if A displaces B from its salt solution, A is more reactive than B.

A more reactive metal displaces a less reactive metal from its compounds in solution or molten form, so if metal A displaces metal B from its salt solution, A is more reactive than B.

Notes

A more reactive metal displaces a less reactive metal from its compounds in solution or molten form; if A displaces B, then A is more reactive than B.

Check yourself

Metal A displaces metal B from the salt solution of B. Which is more reactive?

Metal A + Salt solution of B gives ...

A displaces B, and B displaces C. Which order, most reactive first, is right?

Why are displacement reactions good evidence for the order of reactivity?

• A — correct. Yes!
• B. The more reactive metal is the one that displaces the other.
• They are equally reactive. If they were equally reactive, one would not displace the other.
• Salt solution of B + Metal A. That would mean B displaced A, the reverse of this reaction.
• Salt solution of A + Metal B — correct. Yes!
• Metal A + Metal B only. The metal A goes into solution as its salt, and metal B is set free.
• C, B, A. A displaces B, so A is more reactive than B; B displaces C, so B is more reactive than C.
• B, A, C. A displaces B, so A is more reactive than B.
• A, B, C — correct. Yes!
• Not all metals react with oxygen, water or acids — correct. Yes!
• Every metal reacts in the same way with oxygen. The book says metals differ in how they react with oxygen.
• They need no metal salts. A displacement reaction needs a salt solution (or a molten compound) of the other metal.