Page 61 - ICSE Chemistry 8

5. Frac onal dis lla on is used to separate a mixture of immiscible liquids.

6. We can separate the components of ink by chromatography.
7. We can use a combina on of diff erent separa on techniques when a mixture consists of more than
two components.
8. We can separate a mixture of salt, sand and grain by magne c separa on and sublima on.

Terms to Know

Ma er: Anything which has mass and occupies space
Pure substance: A substance that has a fi xed composi on and fi xed chemical proper es

Element: A substance that cannot be broken down into simpler substances
Mixture: A substance that consists of two or more pure substances such as elements,
compounds or both that retain their individual proper es
Homogenous mixture: A mixture in which the cons tuents are uniformly distributed throughout

Heterogeneous mixture: A mixture in which the cons tuents are distributed non-uniformly
Suspension: A type of mixture in which a component is not dissolved completely into another
component
Emulsion: A type of mixture consis ng of two or more immiscible liquids
Alloy: A metallic mixture of a metal with another metal
Handpicking: A method in which components of a mixture can be separated by picking them with
one’s hand

Sieving: A method in which the components of a mixture are separated using a sieve
Winnowing: A method of separa ng components of a mixture using wind or moving air
Magne c separa on: A process used to separate a mixture which has one of the components made up of iron

Gravita on: A process used for separa ng a mixture when one of the components of a mixture
is much heavier than water and the other component of the mixture is much lighter
than water
Solvent extrac on: A process used to separate components of a mixture based on their rela ve solubility
Frac onal crystallisa on: A process used to separate components of a mixture when the solubility of solid
components varies in the same solvent
Sedimenta on: A process used to separate insoluble solids suspended in a liquid by allowing them
to se le down
Sediments: The solid par cles that se le down in the process of sedimenta on

Supernatant: The clear liquid above the sediments
Decanta on: A process of pouring clear liquid without disturbing the sediments
Filtra on: A process by which insoluble solid par cles can be separated from a liquid by
allowing the mixture to pass through a fi lter

Evapora on: A process by which liquid changes to its vapour state either by hea ng or exposing it
to air

47