Chemistry · Science General

Separation Techniques

842 Questions

Separation techniques involve physical methods to isolate mixtures, including distillation, filtration, and crystallization. Competitive exams frequently test these foundational concepts. Review the exact processes to enhance problem solving speed.

Distillation and evaporationCrystallization processFiltration methodsSeparating dissolved solidsChromatography and mass techniques

Separation Techniques Questions

Multiple choice

Which of the following is opposite process of evaporation?

  1. Condensation

  2. Sedimentation

  3. Decantation

  4. Filtration

  5. Threshing
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The opposite of evaporation is condensation. In evaporation, liquid is changed into vapours whereas the vapours are changed into liquid in condensation. In evaporation, there is heating whereas in condensation there is cooling.

Multiple choice

Which of the following methods of separation is used only by the farmer?

  1. Sedimentation

  2. Threshing

  3. Decantation

  4. Filtration

  5. Sieving
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In threshing, the food grains are separated from the rest of the plant. This is done in the agricultural field. As only farmer works in the agricultural field, this method of separation is used by the farmer only.

Multiple choice

Which of the following method(s) is/are used to separate impurities from wheat commercially?

  1. Handpicking and sieving

  2. Threshing and handpicking

  3. Sieving only

  4. Threshing and sieving
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Impurities in wheat vary in size. On the commercial scale, impurities like husk and stones are removed before grinding wheat by pouring it on a slanting sieve. This removes the pieces of stones, stalk and husk that may still remain after threshing and winnowing. So, apart from winnowing, the two methods are threshing and sieving. 

Multiple choice

Which of the following substances can be separated by wind?

  1. Husk from grains

  2. Grains from stalks

  3. Stones from grains

  4. Sugar from rice and water
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Winnowing is a method in which the heavier particles are separated from the lighter ones due to the difference in their weight. Separation of husk from grains is done using this method. 

Multiple choice

Which of the following sets of methods is used to separate the mixture of salt, water and sand?

  1. Sedimentation and filtration

  2. Sublimation, filtration and evaporation

  3. Filtration, evaporation and condensation

  4. Decantation and crystallisation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Salt is soluble in water but sand is not. Sand being heavier settles at the bottom and can be separated by filtering the mixture. Salt and water can be separated by evaporation as water will evaporate leaving the salt behind. The water vapours can be collected by condensation. So, the methods involved in separating the mixture of sand, water and salt are filtration, evaporation and condensation. 

Multiple choice

A vessel contains a mixture of sugar, rice and water. Rice can be separated by ___, while sugar can be recovered by ____.

  1. filtration, centrifugation

  2. evaporation, condensation

  3. sedimentation, condensation

  4. filtration, evaporation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A mixture of sugar, water and rice can be separated by the process of filtration, which will separate rice from the mixture; followed by evaporation which will separate water from sugar, leaving sugar behind. 

Multiple choice

Which of the following substances can be separated by decantation?

  1. Alcohol from water

  2. Coconut oil from water

  3. Vinegar from water

  4. Water from milk
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Decantation is a method used to separate a mixture of two liquids which do not mix with each other, and form different layers. Oil being lighter stays at the surface and water remains at the bottom, therefore the two can be separated by decantation. 

Multiple choice

The process of evaporation is used to separate __________.

  1. cream from milk

  2. sugar from water

  3. alcohol from water

  4. sand from water
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Evaporation refers to the conversion of a liquid into vapor state. A mixture of sugar and water can be separated by evaporation as water can evaporate but sugar can not.  

Multiple choice

Which of the following pairs are incorrect matched?

  1. Substances that make mixture → components

  2. Removal of salt from pulses → Sedimentation

  3. Separating stones from sand → Sieving

  4. Removal of butter from milk → Decantation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Components are the substances which make a mixture. Pulses can be separated from salt by sedimentation as pulses settle down at the bottom. Sand can be separated from stones by sieving. Butter can be separated from curd by churning and not decantation. 

Multiple choice

On the basis of which principle can a mixture of oil and water be separated?

  1. On the same principle as sedimentation and decantation

  2. On the same principle as condensation and evaporation

  3. On the same principle as filtration and sedimentation

  4. On the same principle as condensation and sedimentation
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The mixture can be separated on the same principle as sedimentation and decantation.