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 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.

Multiple choice chemistry basic analytical techniques partition coefficients solvent extraction separation methods

A mixture contains two solids A and B. Solid A is light in weight while solid B is very heavy. Their sizes are almost same. Here, A is the unwanted component. To get pure solid B, which separation method would you suggest?

  1. sieving

  2. winnowing

  3. magnetic separation

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

Winnowing is a traditional method in water air current is blown to separate particles of light weight and heavier weight.

Multiple choice chemistry basic analytical techniques partition coefficients solvent extraction separation methods

To separate ammonium chloride from common salt, we use:

  1. filtration

  2. sedimentation

  3. sieving

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

Sublimation is a specialized change of state when a solid substance skips the liquid phase and moves directly into the gas phase. This occurs because the substance absorbs energy so quickly from the surroundings that melting never occurs.

Ammonium chloride separated from common salt by sublimation process.

Multiple choice chemistry basic analytical techniques partition coefficients solvent extraction separation methods

You can use decantation to separate:

  1. two miscible liquids

  2. two immiscible liquids

  3. two metals in an alloy

  4. solid-solid mixture
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Decantation is a process for the separation of mixtures of immiscible liquids or of a liquid and a solid mixture such as a suspension. Example sand from water can be separated by decantation.

Multiple choice chemistry basic analytical techniques partition coefficients solvent extraction separation methods

A small boy mischievously mixed small pebbles into a bag of pulses. What method will you employ to separate the mixture?

  1. Magnetic separation

  2. Crystallisation

  3. Handpicking

  4. Filtration
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The method in which substances in a mixture can be separated by just picking them out with the help of hand from the mixture is known as handpicking method. It is one of the various methods which are carried out in dry conditions.