Definition Of Reactivity Series Of Metals
It is an arrangement of metals in decreasing order of their reactivities.
More About Reactivity Series of Metals
- Reactivity Series is also known as Activity Series
- Most reactive metals are at top while Least reactive metals at the bottom
- For any two metals in the series, the metal placed higher in the series can displace lower metals from their salts
- As you move down the series oxides of highly reactive metals like Magnesium and Aluminum are not reduced easily either by Hydrogen or by Carbon
- Metals placed below copper do not rust easily because of their low reactivity
- Metals placed below Hydrogen in the Reactivity series do not react with Acids to produce hydrogen gas
Example:
- Potassium at the top of the series is the most reactive among all the metals of the series.
- Zinc displaces copper from copper sulphate solution to form zinc sulphate and metallic copper. But, Copper do not displaces zinc from zinc sulphate .This is because Zinc is placed above the Copper in the Reactivity Series of metals.
- Zn + CuSO4 → ZnSO4 + Cu
Cu + ZnSO4 → No Reaction - Zinc reacts with dilute hydrochloric acid to produce hydrogen gas, whereas Copper does not react with dilute hydrochloric acid. This is because zinc is placed above the hydrogen while copper is placed below hydrogen in the reactivity series of metals.
- Zn + 2HCl → ZnCl2 + H2
Cu+ 2HCl → No Reaction
Solved Example:
Ques: Identify the metal which replaces zinc from zinc sulphate?
A. Iron
B. Lead
C. Copper
D. Magnesium
Correct Answer: D
Solution: To displace zinc from zinc sulphate, we need a more reactive metal than zinc. In the reactivity series Iron, Lead and Copper placed below Zinc. Magnesium is placed above Zinc. So, only Magnesium can displace Zinc from Zinc sulphate as shown in the balanced chemical equation
Mg + ZnSO4 → MgSO4 + Zn
Ques: When zinc reacts with copper sulphate, the colour of the resultant solution is will be ____
A. Blue
B. Green
C. Pink
D. Colourless
Correct Answer: D
Solution: The original colour of copper sulphate is blue, When it reacts with zinc metal ,copper is displaced by zinc . It results in the formation of zinc sulphate, which is a colourless in aqueous solution
CuSO4 + Zn → ZnSO4 + Cu