Ans. We can convert a saturated solution into an unsaturated solution in the following ways:-
i. by heating the solution
ii. by adding more solvent to the solution
Ans. The salt can be obtained from sea by the process of evaporation.
Sea water is collected in shallow pits and heat of the sun slowly turns water into water vapor and in few days through evaporation, the water evaporates completely leaving behind solid common salt.
Ans. Rain drops attach themselves to dust particles suspended in air, make them heavy and bring them down to the earth that is why sky becomes clear.
Ans. Difference between homogeneous and heterogeneous mixture
1. ‘homo’ means same
1. ‘hetero’ means different
2. It has uniform composition
2. It has non uniform composition
3. It can’t be separated physically
3. It can be separated physically
4. Examples of homogeneous mixtures are: salt in water, sugar in water.
4. Examples of heterogeneous mixtures are: water and sand, oil and water.
Ans. The size of the pores in a sieve depends upon the size of the substance to be separated and the impurities of the mixture.
Ans. A colloid is mixture where at least two types of substances that are not as small as a solution and not as large as a suspension are mixed together. Each substance retains its own properties. Examples: whipped cream, milk, butter, gelatin, jelly, muddy water, plaster, colored glass, and paper.
Ans. The essence of threshing is separation of a cereal grain from the shaft. Threshing is done after harvesting of the crops. This may be carried out in the field or on the farm, by hand or with the help of animals or machines.
Ans. Ceramic candle filters are simple devices made out of clay and used to filter drinking water in order to removes cloudiness, suspended materials and pathogens.
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