Tag: other methods of separation

Quizzes (0) Questions (153)

Questions Related to other methods of separation

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

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

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
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.
Multiple choice chemistry separation of matter sedimentation, decantation and filtration other methods of separation separation methods

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:

  1. $0.75$
  2. $0.5$
  3. $0.65$
  4. $0.85$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In the reaction 2H2 + O2 → 2H2O, if 10 ml of H2 remains after complete water formation, then 30 ml of gas reacted. This 30 ml consists of H2 and O2 in 2:1 ratio, so 20 ml H2 + 10 ml O2 reacted. Initial H2 = 20 ml (reacted) + 10 ml (remaining) = 30 ml. Mole fraction = 30/40 = 0.75. The remaining gas is H2, confirming H2 was in excess.

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

Naphthalene is a volatile solid. It is best purified by:

  1. Crystallisation

  2. Distillation

  3. Steam distillation

  4. Sublimation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sublimation is the process in which a particular solid is converted into gas without changing into liquid. Naphthalene is volatile. It sublimates at room temperature without converting into liquid.

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

Sublimation is a process in which a solid.

  1. Changes into another allotropic form

  2. Changes into liquid form

  3. Changes into vapour form

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Sublimation is a specialized change of state when a solid substance skips the liquid phase and moves directly into the gas phase. This occurs because the substance absorbs energy so quickly from the surroundings that melting never occurs.

Examples:

  •  "Dry ice" or solid carbon dioxide sublimes.
  •  Snow and ice can sublime in the winter months without melting.

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

A mixture of water and NaCl can be separated by?

  1. Sublimation

  2. Evaporation

  3. Decantation

  4. Filtration
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Salt dissolves in water. There is a high difference in their boiling point, so evaporation can be used to remove the water to obtain salt. The water vapours that evaporates can be condensed to form water. Salt is left behind as residue during evaporation.

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

How are the following separated ?
Lead sulphate from a mixture of lead sulphate and lead chloride ?

  1. distillation

  2. filtration

  3. chromatography

  4. evaporation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Lead sulphate is insoluble in water whereas lead chloride is soluble. By dissolving the mixture of lead sulphate and lead chloride in water we can separate the two. After dissolving the mixture in water, lead sulphate can be obtained as the solid that's left behind. Lead chloride can be recovered by evaporating the solution.