Tag: other methods of separation

Questions Related to other methods of separation

Crystallisation is used to purify :

  1. solids

  2. liquids

  3. gases

  4. all of the above


Correct Option: A
Explanation:

Crystallization is used to obtain pure solid from impure solid sample. It is used to purify solids.

The salt we get from sea water can have many impurities in it. These impurities can be removed by :

  1. sedimentation

  2. crystallisation

  3. centrifugation

  4. all of the above


Correct Option: B
Explanation:

Crystallisation is used to obtain pure solid from impure solid sample. It is used to purity solids, e.g., purification of salts that we get from sea.

Separation of crystals of alum from impure sample is carried out through :

  1. centrifugation

  2. distillation

  3. crystallisation

  4. none of the above


Correct Option: C
Explanation:

Pure solids are removed as crystal from the solution through crystallisation. Crystallisation is used to purify solids, e.g., seperation of crystals of alum from impure samples.

While obtaining pure copper sulphate from an impure sample what will finally be obtained in the china dish?

  1. Impurities of the sample are left behind in the china dish

  2. Copper sulphate

  3. Water droplets

  4. Chine dish remains empty


Correct Option: B
Explanation:

When crystallisation is performed to obtain pure copper sulphate from an impure sample, finally crystals of copper sulphate is obtained in the chine dish.

Pure $CuSO _4$ can be obtained from an impure sample by :

  1. crystallisation

  2. galvanisation

  3. centrifugation

  4. sedimentation


Correct Option: A
Explanation:

Crystallisation is a method used to purity solids. Pure $CuSO _4$ in the form of cystals can be obtained from an impure sample by crystallisation.

Why crystallisation is used as a method of obtaining pure $CuSO _4$ from impure sample?

  1. Because $CuSO _4$ is a liquid

  2. Because $CuSO _4$ is a solid

  3. Because $CuSO _4$ is a gas

  4. None of the above


Correct Option: B
Explanation:

Crystallisation is a method used to purify solids. $CuSO _4$ is solid, hence it can be obtained as in a pure cystal form from impure samples using cystallisation.

Crystallization is used to separate :

  1. solid from solid

  2. liquid from solid

  3. solid from liquid

  4. all of above


Correct Option: C
Explanation:

Crystallisation is a sophisticated form of evaporation technique in which crystals of the solute are encouraged to develop during the process of dissolving out from the solution as the solvent evaporates.

X is a solid. Y is a liquid. How can X be separated from a solution of Y?

  1. Sedimentation

  2. Filtration

  3. Crystallization

  4. All of above


Correct Option: D
Explanation:

Sedimentation is the process of separating an insoluble solid from a liquid in which it is suspended by allowing it to settle to the bottom of the container. Filtration is used for separating insoluble solids from a liquid. Crystallisation is a sophisticated form of evaporation technique in which crystals of the solute are encouraged to develop during the process of dissolving out from the solution as the solvent evaporates.

The copper sulphate solution is heated gently on a water bath for :

  1. proper mixing of the sample

  2. evaporation of water

  3. dissolving the copper sulphate in solution

  4. all of above


Correct Option: B
Explanation:

Pure copper sulphate is obtained from an impure sample by re-crystallization. The sample is mixed in water and filtered to remove impurities. It is then heated gently on a water bath for evaporation of water. Thus, a saturated solution is obtained.

While obtaining pure copper sulphate by crystallization, the solution is saturated is indicated by :

  1. change in color

  2. change in consistency

  3. formation of bubbles

  4. formation of crystals near rod


Correct Option: D
Explanation:

During purification of copper sulphate by crystallization, the impure sample is mixed with water and then heated to saturation. The saturation is indicated by dipping glass rod in solution from time to time. Small crystals are formed near the glass rods which indicates saturation.