Tag: chemistry

Questions Related to chemistry

A homogeneous liquid-liquid solution is separated by:

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

  1. distillation

  2. decantation

  3. sublimation

  4. filtration

Show answer
Correct Option: A
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. 

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

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

  1. Passing through $KOH$ solution, then diffusion

  2. Partial evaporation, then diffusion

  3. Preferential liquefaction, then partial evaporation

  4. All of the above

Show answer
Correct Option: A
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.

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

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

  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

Show answer
Correct Option: D
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.

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

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

  1. sedimentation

  2. liquification

  3. distillation

  4. decantation

Show answer
Correct Option: C
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.

_______ is a method of separation that works on adsorption :

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

  1. Crystallization

  2. Chromatography

  3. Gravity separation

  4. Filteration

Show answer
Correct Option: B
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.

State a method to separate a liquid-liquid mixture containing two immiscible liquids having different densities.

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

  1. Separating funnel

  2. Fractional distillation

  3. Distillation

  4. Evaporation

Show answer
Correct Option: A
Explanation:

The two immiscible liquids having different densities can be separated by separating funnel.

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

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

  1. Lighter molecules

  2. Heavy molecules

  3. All molecules equally

  4. None of above

Show answer
Correct Option: A
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.

Fractional distillation is a separation process for :

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

  1. Liquid-liquid

  2. Liquid-solid

  3. Solid-solid

  4. Both b and c

Show answer
Correct Option: A
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.

Membranes used in solubility based gas separation are :

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

  1. Inorganic

  2. Polymeric

  3. Hybrid membrane

  4. All of above

Show answer
Correct Option: D
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.

Which of the following is a type of membrane?

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

  1. Porous

  2. Non-porous

  3. Both a and b

  4. None of above

Show answer
Correct Option: C
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.