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 separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

$\displaystyle { CO } _{ 2 }$ and $\displaystyle CO$ can be separated by :

  1. Chromatography

  2. Solvent extraction

  3. Separation funnel

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

 A gaseous mixture containing CO$ _2$ and CO can be separated by solvent extraction.
The mixture is passed through water.  CO$ _2$ dissolves in water whereas CO does not.

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

______ is useful when one gas is easily liquefiable.

  1. Solvent extraction

  2. Crystallisation

  3. Liquefaction

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

Liquefaction is useful when one gas is easily liquefiable.
Liquefaction of gases is the process by which a gas is converted to a liquid by applying high pressure and low temperature. For example, oxygen normally occurs as a gas. However, by applying high pressure and by reducing the temperature, oxygen can be converted to a liquid.
Note:
In a mixture of NH$ _3$ and H$ _2$, NH$ _3$ gets liquefied under pressure
Liquefaction of gases is the process by which a gas is converted to a liquid. In a mixture of NH$ _3$ and H$ _2$, NH$ _3$ gets liquefied under high pressure and H$ _2$ is left behind.
NH$ _3$ has higher value of the van der Waal's constant 'a' than
Hence, NH$ _3$ is more easily liquefiable than H$ _2$.

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

Which of the following cannot be used for liquid-liquid separation?

  1. Magnet

  2. Sublimation

  3. Crystallization

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

Magnetic separation and sublimation can be used to separate solid from solid. Crystallization is used to recover solid from liquid. Hence, none of the above methods is used for separation of liquid from liquid.

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

A technique in which two liquids are separated by heating process is known as :

  1. distillation

  2. filtration

  3. evaporation

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

Distillation is a process of separating the component or substances from a liquid mixture by selective evaporation and condensation. Distillation may result in essentially complete separation (nearly pure components), or it may be a partial separation that increases the concentration of selected components of the mixture.

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

Fractional distillation is used to obtain the components of which of the following?
I air
II seawater
III muddy water
IV crude oil 

  1. I, II

  2. II, III

  3. I, IV

  4. I, III
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Fraction distillation is based upon the separation of components having very less boiling point difference, therefore components of crude oil and air can be separated using fractional distillation. In the air and in crude oil, the difference in boiling point of different components is very less. 

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

Which of the following technique is used for the separation of a mixture of a liquid and a gas?

  1. Boiling

  2. Sublimation

  3. Crystallization

  4. Fractional distillation
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The technique used for the separation of a mixture of a liquid and a gas is boiling. The gas is removed by application of heat.  With the increase in temperature, the solubility of gas decreases. The gas is collected separately

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

A mixture of hydrogen and chlorine can be seperated by passage through a porous pot.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A mixture of hydrogen and chlorine can be separated by passage through a porous pot. This is because the diffusion of hydrogen more than that of chlorine in the porous pot. So, most of chlorine remains outside the pot.

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

Alcohol and water are best separated from one another by :

  1. distillation

  2. crystallization

  3. manual separation

  4. chromatography

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

Alcohol and water are best separated from one another by distillation. 


Alcohol and water are miscible but they have different boiling points.

If the difference in the boiling points of alcohol and water is less, fractional distillation can be used.

Hence the correct option is A.

Multiple choice separation of components of mixtures methods of separation elements, compounds and mixtures chemistry

Gases are separated from each other by:

  1. fractional evaporation

  2. fractional distillation

  3. fractional crystallisation

  4. fractional sublimation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Gases can be separated by fractional distillation. Firstly, the mixture is cooled until it forms a liquid. This is followed by heating it. The gas with lower boiling point rises in the distillation column & is thus separated.
Multiple choice chemistry petrochemicals and polymers petroleum properties of alkanes petroleum and natural gas rocks and minerals

The crude oil extracted from the earth is separated into its constituents by a process called .....................

  1. disintegration distillation

  2. compound distillation

  3. destructive distillation

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

The constituents of crude oil have a very less difference in their boiling point so they are separated by fractional distillation process.

Multiple choice chemistry petrochemicals and polymers petroleum properties of alkanes petroleum and natural gas rocks and minerals

The first step in refining petroleum is:

  1. fractional distillation

  2. liquation

  3. concentration

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

The very first step in the refining of petroleum oil is Fractional distillation i.e, the fractionation of crude oil in atmospheric vacuum distillation towers. 

The first process in a petroleum refinery is known as distillation. In this process, crude oil is heated and filled into a distillation column.

Multiple choice chemistry petrochemicals and polymers petroleum properties of alkanes petroleum and natural gas rocks and minerals

In the refining of petroleum, in a fractionating column, the principle use is ________.

  1. difference in melting points

  2. difference in boling points

  3. diffrence in freezing points

  4. difference in densities
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A fractional column is an essential item used in the distillation of liquid mixtures so as to separate the mixture into its component parts, or fractions, based on the differences in volatilities. Industrial fractionating columns have outlets at intervals up the column so that multiple products having different boiling ranges may be withdrawn from a column distilling a multi-component feed stream. The lightest products with the lowest boiling points exit from the top of the columns and the heaviest products with the highest boiling points exit from the bottom.

Multiple choice chemistry chemical changes electrochemical reactions electrolysis and its applications electrolytic cells and electrolysis

Which of the following methods can be used to separate hydrogen and oxygen in water?

  1. Boiling

  2. Electrolysis

  3. Distillation

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Electrolysis of ${ H } _{ 2 }O$ helps in separation of ${ H } _{ 2 }O$ to ${ H } _{ 2 }$ & ${ O } _{ 2 }$

${ 2H } _{ 2 }O\longrightarrow { 2H } _{ 2 }+{ O } _{ 2 }$