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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

In a box with a semi-permeable membrane containing a mixture of two gases, the _____________ will pass out of the container more rapidly.

  1. Lighter molecules

  2. Heavy molecules

  3. All molecules equally

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

Gaseous diffusion is based on Graham's law, which states that the rate of effusion of a gas is inversely proportional to the square root of its molecular mass. For example, in a box with a semipermeable membrane containing a mixture of two gases, the lighter molecules will pass out of the container more rapidly than the heavier.

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.

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

Which of the following is a type of membrane?

  1. Porous

  2. Non-porous

  3. Both a and b

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

Porous and non-porous are two types of membrane.
They work through a different mechanism.
Highly selective nonporous membranes must be very thin to achieve reasonable capacities per unit area. This limits their mechanical strength.
Porous membranes typically contain larger voids than non-porous membranes which have interconnected pores significantly larger than the molecular diameters of gases passing through them.