NCERT Class 6 Science Chapter 5: Separation of Substances YouTube Lecture Handouts

Glide to success with Doorsteptutor material for CBSE/Class-6 : get questions, notes, tests, video lectures and more- for all subjects of CBSE/Class-6.

Get video tutorial on: Examrace YouTube Channel

NCERT Class 6 Science Chapter 5: Separation of Substances

Methods of Separation

Hand Picking

  • Slightly larger sized impurities like the pieces of dirt, stone, and husk from wheat, rice or pulses
  • Quantity of impurity is not very large

Threshing

  • Stalks are dried in sun and grains separated
  • Separate grains from stalks (sometimes stalks are beaten by hand, bullocks or machines)

Winnowing

Separate components of mixture based on weight – separate heavy and light components by blowing air

Sieving

Separate bigger impurities from smaller impurities

Removes pieces of stones, stalk and husk that may still remain with wheat after threshing and winnowing.

Illustration: Sieving
Illustration: Sieving

Sedimentation, Decantation & Filtration

When the heavier component in a mixture settles after water is added to it, the process is called sedimentation.

When the water (along with the dust) is removed, the process is called decantation

Filtration - impurities are removed (smaller in size) – used in making soup, juices, paneer (cottage cheese) at home

Illustration: Sedimentation, Decantation & Filtration
Illustration: Sedimentation, Decantation & Filtration
Illustration: Sedimentation, Decantation & Filtration

In a mixture of water and a solid, the heavier particles get settled. The water above the settled particles can be removed. In order to further remove the finer particles, a cloth or a filter paper can be used. Mud can be separated from muddy water by sedimentation, decantation and filtration to give the clear water

Evaporation

Process of conversion of water into vapor – it is continuous wherever water is present

When the salt solution is heated, water gets evaporated leaving behind the salt. Salt from the salt solution can be obtained

💡How to Separate Sand and Salt Mixture?

Conversion of water vapour to liquid form is called as condensation

Solutions

Solute (salt) + Solvent (water) = Solution

Saturated Solution: A given amount of water dissolves only a definite amount of a substance (salt) at a given temperature.

A saturated solution is one in which no more of that substance can be dissolved.

Increase saturation limit by heating

Different substances dissolve to different extent in equal volumes of water

Difference in the size of particles in a mixture is utilized to separate them by the process of sieving and filtration

Mayank