Important Questions Test: Separation of Substances

The process of settling down of particles of a solid in a liquid is known as sedimentation.

Seawater contains a large amount of common salt and the salts of other metals dissolved in it. Near the sea-shore, the sea water is collected in shallow pits and allowed to evaporate in the sunshine. In a few days, the water evaporates, leaving behind salt. Hence it is obtained by evaporation.

Loading process (in chemistry) is the process used to speed up the sedimentation process with the help of chemical called ‘Alum’.

Sedimentation involves settling down of suspended heavy particles present in a mixture at the bottom of the container when left undisturbed for some time. The particles settled down are called sediment. After sedimentation, decantation is carried out by pouring off the liquid to separate the solid sediment.

Churning - The process of separating the constituents of a liquid by agitating it vigorously.

Crystallization of salt is defined as the procedure in which we dissolve the salt in a solvent. Then some of its particles will dissolve and some will continue undisclosed which are the impurities. Thus, we can conclude that the method that is used to get pure salt from impure salt is crystallization.

A solution that has reached the maximum solubility is called a saturated solution . It means you can no longer add solute to the solution . Saturated solution are required for the process of crystallization.

Harmful diseases like jaundice and typhoid are caused by bacteria.

It is distilled water.Because it has been boiled as a vapour and condensed back as a liquid form..
thus, rain water is also known as the purest form of water.

Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase. This is the method used to separate a dissolved solid component from its solution as after evaporation only salt remains.

Milk or curd is churned to separate the butter

Crystallization is the process of slow precipitation of solid crystals of a substance from a concentrated homogeneous solution. The substance is thus obtained in pure crystalline form and has no impurity.

Filtration is the process of separating suspended solid matter from a liquid, by causing the latter to pass through the pores of some substance, called a filter. The liquid which has passed through the filter is called the filtrate.

Ginning: Cotton Ginning is the process of separating the cotton fibers from the cotton seeds. Perfect ginning operation would be performed if the separation of fibers from seed was effected without the slightest injury to either seeds or to the fiber.

Winnowing is the method of separting of a mixture contaning heavier and lighter component by wind is by winnowing air.

Wind winnowing is an agricultural method developed by ancient cultures for separating grain from chaff. It is also used to remove hay and chaff or other pests from stored grain.

Threshing, the loosening of grain or seeds from the husks and straw is the step in the chaff-removal process that comes before winnowing.

This paneer is then separated from the curdled milk by filtering it through a muslin or any other fine cotton cloth.

Pool boiling is the process in which the heating surface is submerged in a large body of stagnant liquid. The relative motion of the vapour produced and the surrounding liquid near the heating surface is due primarily to the buoyancy effect of the vapour that is free convection.

Winnowing is the process of separation of the heavier components from the lighter components of a mixture by wind or by blowing air. It is generally used by farmers to separate the lighter impurities such as husk particles from the heavier grains.

The easiest method to separate mixture of sugar and water is evaporation as it will evaporate water and will leave behind the sugar molecules. 

Saturated solution means solution that is not capable of dissolving more solute at given temperature. If we increase the temperature it can dissolve more solute.

In the case of liquids, a small fraction of particles at the surface, having higher kinetic energy, can break away from the forces of attraction of other particles and gets converted into vapour. The conversion of a liquid into vapours at any temperature below its boiling point is called evaporation.

Hence, the correct option is 'B'.

The clear liquid which passes through the filter paper is called the filtrate.

Aluminium Sulfate, Shortly known as Alum, when added to raw water reacts with the bicarbonate alkalinities present in water and forms a gelatinous precipitate. This floc attracts other fine particles and suspended material in raw water, and settles down at the bottom of the container.

Loading is the process in which alum particles are deposited on suspended clay particles of muddy water to make them heavy and settle down rapidly.

Adding Bleaching powder is the most common technique used to purify the water supplied. It can kill the micro-organisms like protozoans which cause water bone diseases. In places where there are no options to purify water, bleaching powder is the only remedy.

Kerosene oil and water are immiscible liquids. A mixture of the two can be separated with the help of separating funnel. The process is decantation.