Tag: basic analytical techniques

Questions Related to basic analytical techniques

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

Show answer
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

Show answer
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

Show answer
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

Show answer
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.

Sublimation is the procedure in which ___________.

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

  1. solid on heating decompose.

  2. solid on heating directly converts into vapor.

  3. solid on heating converts into solid again

  4. solid on heating converts into liquid

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Correct Option: B
Explanation:

Sublimation is the procedure in which solids on heating directly converts into vapor without converting into liquid phase. 

Fractional crystallization is a method of refining substance based on difference on their:

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

  1. boiling point

  2. solubility

  3. hardness

  4. density

Show answer
Correct Option: B
Explanation:

In fractional crystallization, the component with low solubility will crysatllize first and one with high solubility will crystallize latter, so substances can be refined based on the difference on their solubility.