Mammoth Memory

Displacement from solution

If a metal and metal solution react, the more reactive metal will displace the less reactive metal from solution.

Copper displaces silver

If the metal in solution you start with is formed from a more reactive metal than the metal to be added, no reaction will occur.

You can now predict which metal will win by using the reactivity series of metals.

Note: This can be used as an alternative method of testing to put the reactivity series in the correct order.

Copper is more reactive than silver  

Example 1

Zinc nitrate + Lead → No reaction

 

But

 

Lead nitrate + Zinc → Zinc nitrate + Lead

 

 

 

Example 2

Magnesium nitrate + Lead → No reaction

 

But

 

Lead nitrate + Magnesium → Magnesium nitrate + Lead

 

 

 

Lead nitrate and silver

Lead nitrate + Silver → No reaction
Pb(NO3)2 + Ag → No reaction

 

As no reaction occurs, lead must be more reactive than silver.

No reaction occurred

Lead nitrate and copper

Lead nitrate + Copper → No reaction
Pb(NO3)2 + Cu → No reaction

 

As no reaction occurs, lead must be more reactive than copper.

No reaction occurred

Lead nitrate and zinc

Lead nitrate + Zinc → Zinc nitrate + Lead
Pb(NO3)2 + Zn → Zn(NO3)2 + Pb

 

The zinc displaces the lead from solution to form zinc nitrate, so zinc must be more reactive than lead.

Zinc displaces lead so zinc is more reactive than lead

The zinc turns black as it becomes coated in a layer of lead that’s been displaced from the lead nitrate solution. 

Lead nitrate and magnesium

Lead nitrate + Magnesium → Magnesium nitrate + Lead
Pb(NO3)2 + Mg → Mg(NO3)2 + Pb

 

The magnesium displaces the lead from solution to form magnesium nitrate, so magnesium must be more reactive than lead.

Magnesium displaces lead so magnesium is more reactive than lead

The magnesium turns black as it becomes coated in a layer of lead that’s been displaced from the lead nitrate solution.

Zinc sulphate and magnesium

Zinc sulphate + Magnesium → Magnesium sulphate + Zinc
ZnSO4 + Mg → MgSO4 + Zn

Zinc is less reactive than magnesium, so the solution becomes magnesium sulphate   

The more reactive magnesium displaces the less reactive zinc from the solution to form magnesium sulphate.

Magnesium sulphate and zinc

Magnesium sulphate + Zinc → No reaction
MgSO4 + Zn → No reaction

 diagram of containers of magnesium and zinc and explanation of their reactivity

The less reactive zinc will not react with the solution which contains the more reactive magnesium.

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