i. The property used in separating a mixture of two solid by winnowing is difference in weight.
ii. The chemical used for loading is baking soda.
iii. A mixture of milk and water can be separated by filtration.
iv. A mixture of powdered salt and sugar can be separated by the process of winnowing.
v. Separation of sugar from tea can be done with filtration.
vi. Grain and husk can be separated with the process of decantation.
vii. The method in which stalks are beaten to free the grain seeds is called threshing.
viii. Sieving is used when the component of mixture are of different sizes.
ix. The method of filtration is also used in the process of preparing cottage cheese in homes.
x. When no more salt can be dissolved in the given amount of water at particular temperature, the solution is said to be unsaturated.
xi. Centrifugation is used to separate cream from curd.
xii. Hand picking can be used to separate cashew nuts from mixture of almonds and cashew nuts.
i. We can remove small stones from pulses before cooking by .
ii. The process of separating a liquid from solid sediment is called .
iii. The method of separating seeds of paddy from its stalks is called .
iv. When milk, cooled after boiling, is poured onto a piece of cloth the cream (malai) is left behind on it. This process of separating cream from milk is an example of .
v. Salt is obtained from seawater by the process of .
vi. Impurities settled at the bottom when muddy water was kept overnight in a bucket. The clear water was then poured off from the top. The process of separation used in this example is called .
Ans. sedimentation and decantation
vii. method is used to separate stones from grains.
Ans. Hand picking
viii. Husk from wheat can be separated by .
ix. is used to remove impurities and bran from the flour.
x. The two liquids that do not mix with each other can be separated by .
xi. Salt is obtained from .
Ans. sea water
xii. We see water drops under the plate that has been used to cover a container containing milk that has just been boiled. This is due to process of .
Ans. Hand picking and Threshing
Q4. How can we separate sand from water?
Ans. Sedimentation and Decantation
Q5. Which method can be used to separate soil from mixture of soil and grains?
Q6. Which method would you prefer to separate solid dissolved in liquid?
Q7. Which method farmers use to separate grains from bundles of stalk?
Q8. Which method do you prefer for tea leaves from prepared tea?
Q9. Filtration method is used to separate tea leaves from prepared tea. Which other method can be used?
Q10. List various methods of separation of components from their mixtures.
Ans. Some of the methods are: handpicking, winnowing, threshing, sedimentation, decantation, filtration, evaporation and condensation.
Q11. The process of adding alum to water to fasten sedimentation is called loading. Why has this name been given to the process?
Ans. It is because the suspended light particles become heavy on adding alum.
Ans. Oil floats on water and form separate layer. Separating funnel can be used to separate the two.
Q13. Why are we able to dissolve more solute in a solvent at high temperature?
Ans. We are able to dissolve more solute in a solvent at high temperature because high temperature facilitates dissolving reaction by providing energy to break bonds in the solid.
Q14. Why sieving is not used to separate very small stones from rice grains?
Ans. Sieving is not used to separate very small stones from rice grains because both are of almost same size and both will pass through the holes of the sieve.
Q15. There are 3 beakers half filled with water. Now add 3 spoon of sugar in first beaker, 5 spoon of sugar in second beaker and 7 spoon of sugar in third beaker. Stir the solution of all three beakers. Which solution is more saturated?
Ans. Third beaker
Ans. Winnowing is the method in which heavier components of the mixture are separated from the lighter components such as chaff, dirt, etc. by dropping mixture from height into the air. This method is used by farmers to separate husk and other lighter impurities from grains.
Ans. We need to separate the components of a mixture for the following reasons:
Ans. Husk or dirt particles from a given sample of pulses can be removed by washing the pulses with water. Being heavier, pulses will settle down in the bottom of the container whereas lighter particles will keep floating in the water. This is called sedimentation. Dirty water can be removed by the process of decantation by leaving behind pulses in the bottom of the container.
Ans. Sieving is a simple and convenient technique of separating particles of different sizes by allowing the smaller particles to pass through the holes of a sieve leaving the bigger particle in the sieve.
Uses of sieving
Ans. Sand is insoluble in water. So we can use two methods to separate sand and water from the mixture.