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 chemistry chemistry in daily life food spoilage and food preservation methods of preserving food chemicals in food

Currency notes can be marked with an invisible ink. Thieves can be trapped because this ink

  1. Shows up in ultraviolet light

  2. Turns red on adding alkali

  3. Turns blue on adding acid

  4. It attracted by a magnet
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Invisible ink shows up in ultraviolet light.

Modern UV-invisible ink is mainly made by a fluorescent derived from things in nature that glow when exposed to an UV light.

Multiple choice chemistry separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

Separation of crystals of alum from impure sample is carried out through :

  1. centrifugation

  2. distillation

  3. crystallisation

  4. none of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Pure solids are removed as crystal from the solution through crystallisation. Crystallisation is used to purify solids, e.g., seperation of crystals of alum from impure samples.

Multiple choice chemistry separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

While obtaining pure copper sulphate from an impure sample what will finally be obtained in the china dish?

  1. Impurities of the sample are left behind in the china dish

  2. Copper sulphate

  3. Water droplets

  4. Chine dish remains empty
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When crystallisation is performed to obtain pure copper sulphate from an impure sample, finally crystals of copper sulphate is obtained in the chine dish.

Multiple choice chemistry separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

Crystallization is used to separate :

  1. solid from solid

  2. liquid from solid

  3. solid from liquid

  4. all of above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Crystallisation is a sophisticated form of evaporation technique in which crystals of the solute are encouraged to develop during the process of dissolving out from the solution as the solvent evaporates.

Multiple choice chemistry separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

X is a solid. Y is a liquid. How can X be separated from a solution of Y?

  1. Sedimentation

  2. Filtration

  3. Crystallization

  4. All of above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sedimentation is the process of separating an insoluble solid from a liquid in which it is suspended by allowing it to settle to the bottom of the container. Filtration is used for separating insoluble solids from a liquid. Crystallisation is a sophisticated form of evaporation technique in which crystals of the solute are encouraged to develop during the process of dissolving out from the solution as the solvent evaporates.

Multiple choice chemistry separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

Which method is used to separate diastereomers?

  1. Distillation

  2. Fractional Crystallisation

  3. Sublimation

  4. Evaporation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Diastereomers have different physical properties. You can separate them by ordinary separation techniques such as fractional crystallization. 


Then you treat the separated diastereomers with appropriate reagents to regenerate the original enantiomers.

Option B is correct.

Multiple choice chemistry separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

Crystals of pure copper sulphate are separated from the solution by :

  1. condenstaion

  2. distillation

  3. solidification

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

Pure copper sulphate can be obtained from an impure sample by re-crystallization. The impure sample is dissolved in water, heated and then cooled which then later forms crystals. These copper sulphate crystals are then separated by filtration and drying.

Multiple choice chemistry separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

The principle behind purification by crystallisation is that the :

  1. amount of solute that can be dissolved by a solvent increases with temperature

  2. amount of solute that can be dissolved by a solvent decreases with increase in temperature

  3. both a and b

  4. none of above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Crystallisation is one of the very important purification techniques, purifying substances by removing unwanted by-products. Crystalline compounds are generally purified via this crystallisation process. The principle behind the crystallisation is that the amount of solute that can be dissolved by a solvent increases with temperature.

Multiple choice chemistry separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

Which of the following can be separated by crystallization?

  1. Copper sulphate

  2. Benzoic acid

  3. Potash alum

  4. All of above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Crystallization is a method of purification by the formation of crystals. 


The above samples can be separated by crystallization by heating the solution and then cooling them to form crystals.

Hence the correct option is D.

Multiple choice chemistry separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

Technique utilized to separate a mixture of dissolved solids by evaporation according to individual solubilities.

  1. Distillation

  2. Chromatography

  3. Fractional crystallization

  4. Filtration

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

Technique utilized to separate a mixture of dissolved solids by evaporation according to individual solubilities is fractional crystallization. Two solutes have different solubilities in the same solvent at the same temperature. Fractional crystallization is step-wise crystallization. First, less soluble solute is crystallized out. Later, more soluble solute is crystallized out.

Multiple choice chemistry separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

Why does crystallisation seperate mixtures?

  1. Because the components do not chemically combine

  2. Because the components have different boiling point

  3. Because the components have different solubilities at high and low temperatures

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The crystallization can separate mixtures because the components have different solubilities at high and low temperatures. The solute to be crystallized is more soluble in hot solution than in cold solution.

Multiple choice chemistry separation of matter crystals and crystallisation filtration and crystallisation other methods of separation

The most suitable method of separation of $1$ mixture of ortho and para-nitrophenols is:

  1. crystallisation

  2. steam distillation

  3. sublimation

  4. chromatography
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The most suitable method of separation of 1:1 mixture of ortho and para-nitrophenols is steam distillation because they have a great difference in their boiling points. Hence, option B is correct.