Chemistry · Science General

Separation Techniques

813 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 combinations of separating sand, salt and water is incorrect?

  1. Separation

  2. Sedimentation

  3. Evaporation

  4. Decantation

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

It is correct. The mixture of the sand, salt and water can be separated successfully using a combination of sedimentation, decantation, evaporation and condensation. The separation of solids from gas streams is a common unit operation in production plants. This is called the separation process.

Multiple choice

Which of the following is an example of a component separated from a mixture?

  1. Soil

  2. Seawater

  3. Paneer

  4. Soap

  5. Coking oil
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

It is correct. The method of filtration is used in the process of preparing cottage cheese (paneer) in our homes. For making paneer, a few drops of lemon juice are added to milk as it boils. This gives a mixture of particles of solid paneer and a liquid. The paneer is then separated by filtering the mixture through a fine cloth or a strainer.

Multiple choice

Match the methods of separation in column A from the substances it can be used to separate in Column B:

 
Column A Column B
1. Sieving a. Grains from the stalk
2. Decantation b. Pebbles from sand
3. Threshing c. Oil and water

  1. 1 - a, 2 - b, 3 - c

  2. 1 - b, 2 - c, 3 - a

  3. 1 - b, 2 - a, 3 - c

  4. 1 - c, 2 - a, 3 - b

  5. 1 - a, 2 - c, 3 - b
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

It is correct. All are correctly matched. Sieving can be done to separate pebbles from sand. Decantation can be used to separate oil and water. Threshing is done to separate grains from stalk.

Multiple choice

Which of the following statements is false?

(P) Handpicking allows the good grains to be separated from the waste and impurities. (Q) A mixture of milk and water can be separated by filtration. (R) The method of separating seeds of paddy from its stalks is called threshing. (S) More of a substance can be dissolved in a solution by heating it. (T) Sieving is a method of separating substances that are of different sizes.

  1. P

  2. Q

  3. R

  4. S

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

Yes, it is correct. A mixture of milk and water cannot be separated by filtration.

Multiple choice

Which of the above given statements is/are correct?

Directions: Consider the following statements and answer the question that follows:

1. Filtration can be used to separate components of a mixture of an insoluble solid and a liquid.
2. Water dissolves similar amount of soluble substances in it.
3. When the heavier component in a mixture settles after water is added to it, the process is called decantation.

  1. Only 1

  2. Only 2

  3. Only 3

  4. Both 1 and 2

  5. Both 2 and 3
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

 This statement is correct. Filtration can be used to separate components of a mixture of an insoluble solid and a liquid.

Multiple choice

The process of separation used in this example is called ___________.

Directions: Read the given passage carefully and then complete the statement given below:

Shreya went for a picnic to the forest reserves. They ran out of water and her father collected water from a stream nearby. The water was slightly muddy and her father told her to wait before they could drink it. Soon impurities settled at the bottom when muddy water was kept still. The clear water was then poured off from the top.

  1. distillation

  2. decantation

  3. winnowing

  4. filteration

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

It is correct. Grains can be separated from dirt by sedimentation and decantation. When water is added to the grains, the dust and dirt dissolve in the water, making it muddy. Thus, the dirt and grains are separated. The grains settle at the bottom because they are heavier. This process of the settling of the heavier substance is called sedimentation. Now, the grains can be separated by simply pouring out the water. This process is called decantation.

Multiple choice

There are three examples of separation of substances given above. Which of these three illustrations have followed the method of sedimentation to finally separate the substances?

Directions: Read the given statements carefully and answer the question that follows.

A. The steam that forms on boiling water turns back into water when it comes in contact with a cold metal lid.
B. The grains with dried husk and chaff, are separated and thrown away before the wheat can be used.
C. After a mixture of oil and water is separated, the water left behind can be further cleaned. After this it is further separated, and hence dirt will sift out, leaving the water clean.

  1. A

  2. B

  3. C

  4. All of them

  5. None of them
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Correct. Example A is condensation. Example B is winnowing. Example C is filtration. Thus neither of the examples have used the method of sedimentation. So, none of them is the correct answer.

Multiple choice

When milk is churned, the cream separates from it due to the ________.

  1. rotational force

  2. centrifugal force

  3. centripetal force

  4. both (1) & (2)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When milk is churned, the centrifugal force generated by the rotational motion pushes the denser milk outward, while the lighter cream (which has a higher fat content) accumulates in the center. This is the same principle used in centrifuges to separate substances of different densities.

Multiple choice

Which of the following processes is used for the separation of insoluble solid particles from a solid-liquid mixture, if the solid particles are very small and pass through a filter paper?

  1. Chromatography

  2. Crystallisation

  3. Sublimation

  4. Centrifugation

  5. Distillation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

If the solid particles are very small and pass through a filter paper, then centrifugation process is used for the separation of insoluble solid particles from a solid-liquid mixture. Example: Mixtures of solids and liquids, such as fat in the cream by the process of centrifugation.

Multiple choice

Which of the following is not an application of centrifugation process of separation?

  1. Separation of cream from milk in dairies.

  2. Used in washing machines to squeeze out water from clothes.

  3. Used in laboratories to separate collodial particles from their solutions.

  4. Used in laboratories to separate a mixture of acetone and water.

  5. Used in diagnostic labs for blood and urine tests.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A mixture of acetone and water can be separated by the process of distillation.

Multiple choice

A mixture of n-hexane and n-heptane can be separated through the process of _____________ method.

  1. chromatography

  2. distillation

  3. crystallisation

  4. fractional distillation

  5. centrifugation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In case the difference in the boiling points of the liquids is less than 25 kelvin temperature, we use the fractional distillation method. A mixture of n-hexane and n-heptane can be separated through the process of fractional distillation.