In Displacement reaction,

More reactive metals displace less reactive metals from their compounds

 

Example

Zinc is more reactive than copper

If we take copper sulphate solution and add Zinc to it,

it replaces Copper from Copper Sulphate to form Zinc Sulphate (which is a colourless solution)

However if we do the opposite, there is no reaction

Displacement Reaction.jpg

It is because copper is less reactive than Zinc,so it is not able to replace it from its compound

 

But, how do we know which Metals are more reactive?

To find which metal replaces the other, we have reactivity series of metals

 

Reactivity Series of Metals.jpg

 

Why are Sodium and potassium stored in kerosene.

Sodium and Potassium are highly reactive metals.

They react with moisture(water), oxygen and other gases present in the air.

So,to prevent them from spoiling, sodium and potassium are kept in kerosene oil.

 

Let’s study some more reactions

 

Reaction of Iron Metal with Copper Sulphate

Reaction of iron metal with cooper sulphate.jpg

 

Reaction of Zinc Metal with Iron Sulphate

Reaction of Zinc metal with iron sulphate.jpg

 

Questions

NCERT Question 3 -

Fill in the blanks :

(a) Phosphorus is very……………. non-metal.

(c) Iron………………... is reactive than copper.

Answer

 

NCERT Question 4

Mark ‘T’ if the statement is true and ‘F’ if it is false.

(b) Sodium is a very reactive metal. ( )

(c) Copper displaces zinc from zinc sulphate solution. ( )

Answer

 

NCERT Question 6 (c)

Give reasons for the following :

(c) Copper cannot displace zinc from its salt solution.

View Answer

 

NCERT Question 9 -

What happens when

(a) Dilute sulphuric acid is poured on a copper plate?

(b) Iron nails are placed in copper sulphate solution?

    Write word equations of the reactions involved.

Answer

 

  1. Class 8
  2. Chapter 4 Class 8 - Materials : Metals And Non-Metals

Transcript

Displacement Reaction Zinc is more reactive than copper Zinc + Copper Sulphate Zinc Sulphate + Copper (Zn) (CuSO4) (ZnSO4) (Cu) (Silvery White) Compound of Copper It is blue in color Compound of Zinc It is colorless (Red brown) But Copper + Zinc Sulphate (Cu) (ZnSO4) No Reaction Reactivity Series of Metals Most reactive metal Decreasing chemical reactivity Least reactive metal Reaction of Iron Metal with Copper Sulphate Iron is more reactive than copper Iron + Copper Sulphate Iron Sulphate + Copper (Fe) (CuSO4) (FeSO4) (FeSO4) (Cu) (Grey) Compound of Copper It is blue in color Compound of Iron It is green in color (Red brown) But Copper + Iron Sulphate (Cu) (FeSO4) No Reaction Reaction of Zinc Metal with Iron Sulphate Zinc is more reactive than iron Zinc + Iron Sulphate Zinc Sulphate + Iron (Zn) (FeSO4) (ZnSO4) (Fe) (Silvery White) Compound of Iron It is green in color Compound of Zinc It is colorless (Grey) But Iron + Zinc Sulphate No Reaction (Fe) (ZnSO4)

About the Author

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.