Tag: other methods of separation

Questions Related to other methods of separation

Evaporation is used to seperate:

  1. salt from water

  2. pepper and sand

  3. sand and water

  4. camphor and $NaCl$


Correct Option: A
Explanation:

The answer is salt from water.
Evaporation is used to separate a non-volatile soluble salt from a liquid. On heating, the liquid evaporates and soluble salt remains behind.

Copper sulphate dissolved in water can be recovered as solid by:

  1. Evaporation

  2. Filtration

  3. Centrifugation

  4. All of above


Correct Option: A
Explanation:

Evaporation is used to separate a soluble solid from a liquid. For example, copper sulfate is soluble in water its crystals dissolve in water to form copper sulfate solution. During evaporation, the water evaporates away leaving solid copper sulfate crystals behind.

The process of _________ is used to separate the component from a solid-solid mixture which _________ on heating and the other component being non-volatile.

  1. sublimation, soluble

  2. sublimation, sublimes

  3. chromatography, soluble

  4. centrifugation, sublimes


Correct Option: B
Explanation:

The process of sublimation is used to separate the component from solid-solid mixture which sublimes on heating and the other component being non-volatile.

Camphor can be separated using :

  1. distillation

  2. sublimation

  3. fractional distillation

  4. centrifugation


Correct Option: B
Explanation:

Camphor is a solid that gets converted to gas without changing to liquid. Hence, it can be separated by sublimation provided the other substance in non-volatile. It is highly volatile.

The salt can be easily obtained from the salty water by the process of

  1. Evaporation

  2. Chromatography

  3. Crystallization

  4. Both a and b


Correct Option: A
Explanation:

The process of conversion of water into vapour by heating it to its boiling point is called evaporation.The salt can be easily obtained from the salty water by the process of evaporation. If we boil this water, the water evaporates completely, leaving behind only the salt.

 Sublimation is a technique that helps chemists to:

  1. break

  2. purify

  3. melt

  4. freeze


Correct Option: B
Explanation:

Sublimation is a technique that helps chemists to purify. During sublimation, upon heating, a solid substance is converted to the gas phase without passing through the liquid phase.  A solid is heated under vacuum. The solid volatilizes and condenses as a purified compound on a cooled surface, a non-volatile residue of impurities is left behind.

Sublimation requires additional energy and is an:

  1. endothermic change

  2. exothermic change

  3. both a and b

  4. none of above


Correct Option: A
Explanation:

Sublimation is the process of transferring molecules in the solid phase to the gaseous phase. Since liquid state is skipped in this process, a large amount of energy has to be supplied in order to provide the required molecular motion to the molecules. Hence it is an endothermic change

Solid which undergoes sublimation is :

  1. argon

  2. iodine

  3. sodium chloride

  4. water


Correct Option: B
Explanation:

solids undergo sublimation at low pressures (under vacuum). At standard, atmospheric pressure, a few solids which will sublime are iodine (at slightly higher than room temperature),

Statement I: Evaporation is an endothermic process.
Statement II: Heat is absorbed as a substance cools.

  1. Both Statement I and Statement II are correct and Statement II is the correct explanation of Statement I.

  2. Both Statement I and Statement II are correct, but Statement II is not the correct explanation of Statement I. 

  3. Statement I is correct, but Statement II is incorrect.

  4. Statement I is incorrect, but Statement II is correct.


Correct Option: C
Explanation:

Option C is the correct answer.

Evaporation is an endothermic process. Because, evaporation requires heat. When heat is given into the system, evaporation from the system occurs.
When a substance cools down, it gives off heat in its surrounding. Thus, heat is not absorbed, rather heat is given out into the surrounding for the substance to cool.

A mixture of glucose water can be separated by the method of evaporation.

  1. True

  2. False

  3. Either

  4. Neither


Correct Option: A
Explanation:

A mixture of glucose water can be separated by the method of evaporation. Water will evaporate and glucose is left behind.