Tag: filtration and crystallisation

Questions Related to filtration and crystallisation

Which of the following mixtures cannot be separated by sublimation?

chemistry basic analytical techniques filtration and crystallisation other methods of separation separation techniques

  1. Salt and ammonium chloride

  2. Salt and naphthalene

  3. Salt and camphor

  4. Camphor and naphthalene

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Correct Option: D
Explanation:

Sublimation is the transition of a substance directly from the solid to the gas phase without passing through the intermediate liquid phase. Ammonium chloride, camphor, anthracene, napthalene can sublime but common salt cannot sublime. Hence, option D is correct.

The change of solid into vapours on heating and of vapours into solid on cooling is called :

chemistry basic analytical techniques filtration and crystallisation other methods of separation separation techniques

  1. sublimation

  2. condensation

  3. distillation

  4. all of above

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Correct Option: A
Explanation:

There are many substances which are converted into gas from solid when heated, and converted from gas to solid when cooled without converting into liquid. Such substances are known as sublime and the proce3wss is called sublimation.

During sublimation of ammonium chloride and salt mixture, _________ is the sublimate.

chemistry basic analytical techniques filtration and crystallisation other methods of separation separation techniques

  1. salt

  2. sand

  3. ammonium chloride

  4. all of the above

Show answer
Correct Option: C
Explanation:

Ammonium chloride changes directly from solid to gaseous state on heating. Hence, on heating ammonium chloride, it gets converted into white vapours. The gaseous form of ammonium chloride can be cooled easily to get a pure solid.

What acts as a sublimate during sublimation of ammonium chloride and salt mixture?

chemistry basic analytical techniques filtration and crystallisation other methods of separation separation techniques

  1. Salt

  2. Sand

  3. Ammonium chloride

  4. All of above

Show answer
Correct Option: C
Explanation:

Ammonium chloride changes directly from solid to gaseous state on heating. The gaseous form of ammonium chloride can be cooled easily to get a pure solid. Hence, it acts as a sublimate.

Which technique is used to separate salt from the filtrate after sublimation of ammonium chloride? 

chemistry basic analytical techniques filtration and crystallisation other methods of separation separation techniques

  1. Evaportion

  2. Condensation

  3. Centrifugation

  4. All of the above

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Correct Option: A
Explanation:

Evaporation technique is used to separate salt from the filtrate. Common salt does not decompose during evaporation. As the water evaporates, fewer and fewer water molecules are present to keep the salt particles apart. The salt therefore recrystallizes and can be collected.

Why is it difficult to separate salt and ammonium chloride mixture and sublimation is the only method to do so?

chemistry basic analytical techniques filtration and crystallisation other methods of separation separation techniques

  1. Both are white in colour

  2. Both are soluble in water

  3. Both A and B

  4. None of these

Show answer
Correct Option: C
Explanation:

Both salt and ammonium chloride are white in colour and soluble in water. They can't be separated by any other method except sublimation.

In the procedure of sublimation, the inverted funnel in plugged with cotton, because __________.

chemistry basic analytical techniques filtration and crystallisation other methods of separation separation techniques

  1. cotton stops external air to enter in funnel

  2. cotton helps in sublimation

  3. ammonium chloride is a evaporating substance, which directly evaporate on heating without converting into liquid phase.

  4. all of these

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Correct Option: C
Explanation:

During separation procedure of ammonium chloride from salt by evaporation an inverted funnel is used which is plugged with cotton boll, so that ammonium chloride do not evaporate.

Which of the fractions will be present maximum in precipitate?

chemistry basic analytical techniques filtration and crystallisation other methods of separation separation techniques

  1. Least soluble substance

  2. Most soluble substance

  3. Both of the above

  4. None of the above

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Correct Option: A
Explanation:

The component which is less soluble will get precipitated out and settle at the bottom and other component which is more soluble will remain in the solution

so, the least soluble substance will be maximum in precipitate.

In the process of separation of ammonium chloride from the salt, ammonium chloride molecule ________. 

chemistry basic analytical techniques filtration and crystallisation other methods of separation separation techniques

  1. evaporate

  2. sublime

  3. crystallize

  4. all of these

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Correct Option: B
Explanation:

The ammonium chloride molecule in separation from salt sublime and get separated. This is a sublimation process which is used to separate two solids. Here salt being non-volatile does not undergo sublimation. 

Which of the following is not a way to separate the components of a mixture?

chemistry basic analytical techniques filtration and crystallisation other methods of separation separation techniques

  1. Evaporation

  2. Electrolysis

  3. Chromatography

  4. Sublimation

Show answer
Correct Option: B
Explanation:

In Electrolysis, the current is passed through the solution and compound gets ionised, with electrolysis we can separate hydrogen and oxygen from pure water, but we can't use this method to separate components of a mixture.