A pure substance is made up of
Only one kind of molecules
Two or more kinds of molecules
Different types of molecules
None
Pure substances possess
Variable melting points and boiling points
Nonuniform
Variable properties
Fixed melting points and boiling points
Which of the following property is not considered when the components of a mixture is separated ?
Density
Energy - change
Volatile nature
Boiling point
We separate mixtures to
Remove unwanted components
To get pure substances
Both the above
None of these
From the following which one is not a mixture.
Alum
A platinum bangle
A gold chain of 22 ct.
Blank ink
The process by which a solid changes directly into gas is called
Decantation
Sublimation
Condensation
Sedimentation
To separate ammonium chloride from common salt, we use
Filtration
Sieving
Identify the mixture from the following
Carbon dioxide
Iron
Hydrogen
Air
Winnowing is useful only when
Two solids have different melting points
Two solids have different boiling points
Two solids have different magnetic properties
Two solids have different weights
A few coloured glass pieces that are big in size are mixed with sugar. The easiest way to separate them is
Heat the mixture
Add the mixture to water
Handpick the glass pieces
Handpick the sugar particles
