Is matter around us pure of Class 9
A heterogeneous mixture of insoluble particles of solute, spread throughout a solvent, is called a suspension. The particle size (diameter) in a suspension is more than 10-5 cm. The particles has a tendency to settle down at the bottom of the vessel and can be filtered out, because their size is bigger than the size of the pores of the filter paper.
- Milk of magnesia is a suspension of magnesium hydroxide, Mg(OH)2, in water.
- Lime water (used for white wash) is a suspension of calcium hydroxide in water.
- Paints are suspensions of coloured substances in water or some other liquid.
- Bleaching powder in water is also a suspension since bleaching powder is insoluble in water.
- The particles of suspension are visible to the naked eye.
PROPERTIES OF SUSPENSION:
- A suspension is a heterogeneous mixture.
- The solid particles of a suspension are so large in size (more than 10-5 cm or 10-7 m or 100 nm) that they are visible to the naked eye.
- The particles of a suspension scatter a beam of light passing through it and makes its path visible (show tyndall effect).
- The solid particles of a suspension settle down when it is allowed to stand for sometime. In other words, a suspension is unstable.
- The particles of a suspension cannot pass through a filter paper. Thus, when a suspension is filtered, the solid particles remain as a residue on the filter paper.
- Suspensions are either opaque or translucent.
- Purification of water
- PHYSICAL AND CHEMICAL CHANGES
- PURE SUBSTANCE
- Reasons of air as a mixture
- Reasons of water as a compound
- Reasons of alloys as mixtures
- TRUE SOLUTION
- COLLOIDAL SOLUTION
- DIFFERENCE BETWEEN TRUE SOLUTIONS AND COLLOIDAL SOLUTIONS
- DIFFERENCE BETWEEN COLLOIDAL SOLUTIONS AND SUSPENSIONS
- SEPARATION OF A MIXTURE
- SEPARATION OF GASES FROM AIR
- Solved questions
- Exercise 1
- Exercise 2
- Exercise 3
- Exercise 4 (Fill in the blanks)
- Exercise 5 (True and False)
- Exercise 6 (Subjective)