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

A single container wherein the enrichment process takes place through gaseous diffusion is called

  1. Divider

  2. Diffuser

  3. Stalk

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

In a box with a semi-permeable membrane containing a mixture of two gases, the lighter molecules will pass out of the container more rapidly than the heavier molecules. The gas leaving the container is somewhat enriched in the lighter molecules, while the residual gas is somewhat depleted. A single container wherein the enrichment process takes place through gaseous diffusion is called a diffuser.

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

Which of the following are the drawbacks of gaseous diffusion methods for separation of gases?

  1. Making and maintaining a suitable barrier

  2. Large energy consumption

  3. Long equilibrium times

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

Gaseous diffusion is unlikely to be the preferred technology of a proliferator due to difficulties associated with making and maintaining a suitable barrier, large energy consumption, the requirement for procuring large quantities of specialized stage equipment, large in-process inventory requirements, and long equilibrium times.

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

Which of the following is commonly used for removing the water layer from a system containing oil and water?

  1. Thermometer

  2. Separatory funnel

  3. Fiame spectrophotometer

  4. Burette

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

Water and oil are immiscible and they form two separate layer, oil have less density than water, so it floats on the water surface so, the water and oil layer can easily be separated by the separatory funnel.

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

During distillation, some porcelain chips are added to the mixture being distilled to ______________.

  1. make the distilling flask more stable

  2. purify the mixture

  3. raise the temperature

  4. make the boiling smoother
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Procelain chips are added to the mixture for two reasons: to prevent the superheating of liquid and to make the distilling flask more stable.

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

An azeotropic mixture cannot be separated into its components by fractional distillation.

  1. True

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

An azeotropic mixture cannot be separated into its components by fractional distillation because, when an azeotrope is boiled, the vapor has the same proportions of constituents as the unboiled mixture. The statement is true  

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

A homogeneous liquid-liquid solution is separated by:

  1. distillation

  2. decantation

  3. sublimation

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

Distillation is a method of separating mixtures based on differences in their volatiles in a boiling liquid mixture. Distillation is a unit operation, or a physical separation process, and not a chemical reaction. Water is distilled to remove impurities, such as salt from seawater. 

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

Explain how individual gases can be separated from a gaseous mixture of $O _2$, $H _2$ and $CO _2$.

  1. Passing through $KOH$ solution, then diffusion

  2. Partial evaporation, then diffusion

  3. Preferential liquefaction, then partial evaporation

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

Individual gases can be separated from a gaseous mixture of $O _2$, $H _2$ and $CO _2$ passing through $KOH$ solution, then diffusion. $KOH$ will absorb $CO _2$ gas. $O _2$ and $H _2$ have different rates of diffusion as they have different molecular weights.

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

How will you separate dioxide, from the mixture of carbon monoxide and carbon dioxide?

  1. By passing through water under high pressure

  2. By passing through concentrated NaOH solution

  3. by passing through ammonical cuprous

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

The mixture of carbon monoxide and carbon dioxide can be separated by passing the mixture through water under high pressure or through concentrated NaOH solution.Also mixture can be separated by passing it through ammonical cuprous.

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

To separate a mixture of two or more gases ___________ method is used.

  1. sedimentation

  2. liquification

  3. distillation

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

To separate a mixture of two or more miscible liquids for which the difference in boiling points is less than 25 K, fractional distillation process is used.

For example, for the separation of different gases from air.

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

_______ is a method of separation that works on adsorption :

  1. Crystallization

  2. Chromatography

  3. Gravity separation

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

Chromatography is a method of separation that works on adsorption. Different components of the mixture have different affinities for the stationary phase and the mobile phase. In other words, the extent of adsorption on the stationary phase, is different for different components of the mixture.

Due to this,  different components of the mixture travel at different speeds. This results in the separation.

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

Fractional distillation is a separation process for :

  1. Liquid-liquid

  2. Liquid-solid

  3. Solid-solid

  4. Both b and c
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fractional distillation is a separation process for liquid-liquid mixture into its component parts, or fractions.
The separation depends on the difference in the  boiling point (usually 25 $^o$C at 1 atm) of individual components. The mixture is heated to a temperature at which one or more fractions of the compound will vaporize.   
For boiling point difference greater than 25 $^o$C, a simple distillation is used.

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

Membranes used in solubility based gas separation are :

  1. Inorganic

  2. Polymeric

  3. Hybrid membrane

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

Membranes used in solubility based gas separation are inorganic, polymeric and hybrid membranes.
Microporous inorganic membranes are usually amorphous in nature and formed from metals, ceramics, or pyrolyzed carbon. The use of polymer membrane has generated an increasing interest in gas separation. Also different types of membrane has been used to enhance gas separation.