Which separation techniques will you apply for the separation

of the following?

(a) Sodium chloride from its solution in water.

(b) Ammonium chloride from a mixture containing sodium

chloride and ammonium chloride.

(c) Small pieces of metal in the engine oil of a car.

(d) Different pigments from an extract of flower petals.

(e) Butter from curd.

(f) Oil from water.

(g) Tea leaves from tea.

(h) Iron pins from sand.

(i) Wheat grains from husk.

(j) Fine mud particles suspended in water.

 

Answer

(a) Sodium chloride from its solution in water - Evaporation

(By heating the solution of sodium chloride, water will evaporate and sodium chloride can be obtained)

 

Evaporation

 

 

(b) Ammonium chloride from a mixture containing sodium

chloride and ammonium chloride - Sublimation

 

(Upon heating, ammonium chloride being a sublimable substance will sublimate to vapours and sodium chloride will be left in the china dish. The vapours of ammonium chloride cool down and settle on the funnel and can be obtained from there.)

 

Sublimation

 

(c) Small pieces of metal in the engine oil of a car - Filtration

 

(Taking an appropriate filter paper, oil will pass through it but small pieces of metal will not. Hence, the two will get separated)

 

Filtration

 

(d) Different pigments from an extract of flower petals - Chromatography

 

The process of Chromatography

 

(e) Butter from curd - Centrifugation

(In this case,mixture is rotated/spinned (moved to go round) leading to denser particles(curd) moving down while lighter particles(butter) move up and hence get separated.)

 

Mechanism of centrifugation

 



(f) Oil from water - Using Separating funnel

(Oil and water are immiscible liquids. They form 2 different layers upon mixing and hence can be separated by using a separating funnel.)

 

Using separating funnel to segregate oil from water

 



(g) Tea leaves from tea - Filtration

(Tea can pass through filter paper, while tea leaves can not. This way they get separated with the help of a filter paper.)



(h) Iron pins from sand - Using a magnet

(Iron pins get attracted to magnets while sand does not. This way they can be separated using a magnet.)

 

Using a magnet to separate iron filings from sand

 



(i) Wheat grains from husk - Winnowing

(Husk being lighter than wheat grains gets blown away when the mixture is tossed in air)

 

Winnowing

 



(j) Fine mud particles suspended in water - Centrifugation  

( The density of mud particles and water is different. Upon centrifugation, mud being denser moves down in the mixture while water moves up and hence the two get separated.)

  1. Class 9
  2. Chapter 2 Class 9 - Is Matter Around Us Pure

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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.