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 organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

The fragrance of the flower is due to the presence of some steam volatile organic compounds called essential oils. These are generally insoluble in water at room temperature but are miscible with water vapour in the vapour phase. A suitable method for the extraction of these oil from the flower is:

  1. distillation

  2. crystallisation

  3. distillation with reduced pressure

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

As the component is miscible with water vapour in vapour phase so steam distillation will be most suitable method for extraction.

Multiple choice chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

Glycerin can be purified by:

  1. vacuum distillation

  2. simple distillation

  3. steam distillation

  4. fractional distillation
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The liquids which decompose at its boiling point can be purified by vacuum distillation. Glycerol decomposes at its boiling point (563K). It can be distilled by vacuum distillation without decomposition at 453K and under 12mm Hg pressure.
Multiple choice chemistry organic chemistry : some basic principles and techniques methods of purification of organic compounds methods of purification - organic compounds biochemical techniques

Distillation under reduced pressure is generally used to purify those liquid which:

  1. have very low boiling points

  2. are volatile

  3. have high boiling points and which decompose below their boiling points

  4. have a large difference in their boiling points.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Distillation under reduced pressure lowers the boiling point of a liquid, which prevents the thermal decomposition of substances that are heat-sensitive. This technique is essential for liquids with high boiling points that would otherwise break down before reaching their boiling point at atmospheric pressure.

Multiple choice chemistry change around us physical changes changes and their classification physical changes

A mixture of sand and salt can be separated by:

  1. Sublimation

  2. Sieving

  3. Dissolving salt and sand mixture in water and then filtration

  4. Dissolving salt in water and then distillation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Dissolving salt in water and then distillation
Process to separate sand and salt from the mixture :
Step 1: Add water to the mixture and stir until the salt dissolve.
Step 2: Turn your burner on and then keep the mixture over it.
Step 3: Pour the water mixture through a very fine strainer or cheese cloth filter . (Sand will remain in filter, salt and water will pass through it)
Step 4: Pour the water and salt mixture back into the burner . And allow the water to boil away and collect salt from there.

Multiple choice chemistry change around us physical changes changes and their classification physical changes

Which of the following  laboratory technique would not bring a physical change in the components of a mixture?

  1. Chromatography

  2. Precipitation

  3. Filtering

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

Physical change would not be in the components of a mixture by Filtering.
Filtering just separates solids from liquids. It does not involve any phase change.

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

Diffusion technique of separation can be used for :

  1. Separation of oxygen from air

  2. Recovery of hydrogen in oil refinery

  3. Separation of methane in bio gas

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

Gas mixtures can be effectively separated by synthetic membranes made from polymers such as poly-amide or cellulose acetate, or from ceramic materials. It can be used for separation of nitrogen or oxygen from air. Helps in Recovery of hydrogen in oil refinery processes. Also used in Separation of methane from the other components of bio gas.

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