Tag: methods of separation

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Questions Related to methods of separation

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.

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

In a mixture of $NH 3$NH3 and $H _2$, _____ Gets liquified under pressure :

  1. $\displaystyle { H } _{ 2 }$
  2. $\displaystyle { NH } _{ 3 }$
  3. $\displaystyle { H } _{ 2 }O$

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

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.
Note: NH$ _3$ has a higher value of the van der Waal's constant 'a' than $H _{2}$
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

______ 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$.