Tag: sedimentation, decantation and filtration

Questions Related to sedimentation, decantation and filtration

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

chemistry separation of matter sedimentation, decantation and filtration other methods of separation separation methods

  1. Evaporation

  2. Chromatography

  3. Crystallization

  4. Both a and b

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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:

chemistry separation of matter sedimentation, decantation and filtration other methods of separation separation methods

  1. break

  2. purify

  3. melt

  4. freeze

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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:

chemistry separation of matter sedimentation, decantation and filtration other methods of separation separation methods

  1. endothermic change

  2. exothermic change

  3. both a and b

  4. none of above

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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 :

chemistry separation of matter sedimentation, decantation and filtration other methods of separation separation methods

  1. argon

  2. iodine

  3. sodium chloride

  4. water

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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.

chemistry separation of matter sedimentation, decantation and filtration other methods of separation separation methods

  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.

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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.

chemistry separation of matter sedimentation, decantation and filtration other methods of separation separation methods

  1. True

  2. False

  3. Either

  4. Neither

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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.

Sublimation is the process of separating a liquid from its solution by evaporating it and then condensing its vapour.

chemistry separation of matter sedimentation, decantation and filtration other methods of separation separation methods

  1. True

  2. False

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Correct Option: B
Explanation:
The answer is $false$.

Sublimation is the process by which a solid directly converts into gas without undergoing liquid state or vice versa. 
For example, naphthalene.

A $40\ ml$ of a mixture of ${ H } _{ 2 }$ and ${ O } _{ 2 }$ at $18\ ^0C$ and $1\ atm$ pressure was parked so that the for water was complete. The remaining pure gas had a volume of $10\ ml$ at 18 $^0C$ and $1\ atm$ pressure, the remaining gas was ${ H } _{ 2,}$ the mole fraction of ${ H } _{ 2 }$ in the $40\ ml$ mixture is:

chemistry separation of matter sedimentation, decantation and filtration other methods of separation separation methods

  1. $0.75$

  2. $0.5$

  3. $0.65$

  4. $0.85$

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Correct Option: A

The rate of evaporation increase with increasing:

chemistry separation of matter sedimentation, decantation and filtration other methods of separation separation methods

  1. surface area

  2. temperasture

  3. humidity

  4. wind speed

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Correct Option: A,B,D

Sublimation cannot be used for purification of 

chemistry separation of matter sedimentation, decantation and filtration other methods of separation separation methods

  1. Urea

  2. Camphor

  3. Benzoic acid

  4. Naphthalene

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Correct Option: A