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

What type of liquids can be separated by the method of fractional distillation?

  1. Liquids with same boiling point.

  2. Liquids with same melting point.

  3. Liquids which differ in their boiling points by 20°C or more.

  4. Liquids which differ in their boiling points by less than 20°C.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Fractional distillation is used for separating liquids which differ in their boiling points by 20°C or more.

Multiple choice

Given below are the Rf values of some amino acids in two different solvents. The chromatography was carried out using whatman paper and the mode was ascending.

   
Amino acid Rf value N – butanol – acetic acid – water
(4 : 1 : 5) N – butanol– pyridine water
(1 : 1 : 1)
Aspartic acid 23 20
Alanine 30 37
Glycine 23 29
Histidine 1 24
Leucine 70 60
Lysine 12 13
Tyrosine 45 63

Which of the following pairs of amino acids will not be completely resolved by N – butanol : acetic acid : water (4 : 1 : 5)?

  1. Aspartic acid and glycine

  2. Histidine and gilycine

  3. Leucine and tyrorine

  4. Alanine and glycine
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In paper chromatography, compounds with identical Rf values in a given solvent system cannot be separated. Aspartic acid and glycine both have Rf=23 in the N-butanol-acetic acid-water (4:1:5) system, meaning they will migrate the same distance and remain unresolved.

Multiple choice

Which of the following methods of separation is used to separate tea leaves from the prepared tea?

  1. Filtration

  2. Hand picking

  3. Threshing

  4. Sedimentation

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

We use the method of filtration to separate the tea leaves from the prepared tea. The tea strainer is held in the hand while pouring the tea in the cup. The liquid tea is poured into the cup, and the tea leaves remain in the strainer. This method is called filtration. 

Multiple choice

The method of separation that is used at construction sites is

  1. hand picking

  2. winnowing

  3. threshing

  4. sieving

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

Sieving is a method of separation, which is used at construction sites. In this process, the stones or pebbles are separated from sand by sieving. Sand is needed at construction sites for construction like buildings, temples etc.

Multiple choice

Kerosene oil and water can be separated by the process of

  1. filtration

  2. decantation

  3. hand-picking

  4. threshing

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

Kerosene oil and water can be separated by the process of decantation by using a separating funnel. Kerosene oil does not dissolve in water and forms a seperate layer. As kerosene is lighter, it would remain in the separating funnel and water being heavier would fall down in the beaker.

Multiple choice

Which of the following is not an example of filtration?

  1. Separating tea leaves from liquid tea

  2. Separating the seeds from the juice prepared

  3. Separating the impurities from tap water

  4. Separating grains from the rest of the plant

  5. Separating mud from water
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Separating grains from the rest of the plant is an example of threshing, not filtration. 

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.