Page 1 - Lesson Note

SAI INTERNATIONAL SCHOOL
CLASS- VI
SUBJECT- CHEMISTRY
TOPIC –SEPARATION OF SUBSTANCES
SUB-TOPIC- METHODS OF SEPARATION- SEPARATION OF SOLIDS
FROM LIQUIDS

LESSON NOTES

SEPARATION OF SOLIDS FROM SOLID-LIQUID MIXTURES:

Solid substances may be either soluble or insoluble in a liquid. Substances like sugar
and salt that dissolve in water are said to be soluble. Substances like sand and chalk do
not dissolve in water are said to be insoluble.

Different methods are used for separating soluble and insoluble substances from their
mixtures.

SEPARATING INSOLUBLE SOLIDS FROM LIQUIDS:

Sedimentation and decantation:

Sedimentation is the process of settling down of heavier, insoluble components in a
mixture. The particles that settle down are called sediments and the clear liquid that
remains on top is the supernatant.

Decantation is the process of pouring out the supernatant liquid slowly into another
container without disturbing the sediment.

Example: A mixture of sand and water is allowed to stand for some time. Settling of the
sand at the bottom of the container is sedimentation. Pouring of the clear liquid from the
top to another container is decantation.

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