Tag: filtration and crystallisation

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Questions Related to filtration and crystallisation

Multiple choice chemistry separation of matter filtration and crystallisation other methods of separation separation techniques

Crystallisation is better than simple evaporation because :

  1. some impurities may remain in the solution after filtration

  2. some solids decompose or heating

  3. both A and B

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

Some solids decompose or some, like sugar, may get charred on heating to dryness. Some impurities may remain dissolved in the solution even after filtration. On evaporation these contaminate the solid. So, crystallisation is better than evaporation.

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

When a mixture of common salt and ammonium chloride is heated, white fumes are liberated which change into a white deposit when cooked. What is this substance?

  1. Ammonium chloride

  2. Common salt (sodium chloride)

  3. A mixture of ammonium chloride and common salt

  4. Ammonium sulphate
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When a mixture of common salt and ammonium chloride is heated, white fumes are liberated which changes into a white deposit when cooked. This white substance is ammonium chloride. Salt and Ammonium chloride are separated by the method of sublimation.

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

Mixute of ammonium chloride and sodium chloride can be seperated by :

  1. distillation

  2. chromatography

  3. sublimation

  4. all of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Substances like camphor, ammonium chloride, naphthalene, benzoic acid, iodine sublime on heating.
$\underset{(Impure)}{Solid}    \xrightarrow{\Delta}     vapour     \xrightarrow{cool}    \underset{Sublimate}{solid(pure)}$

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

A mixture of barium sulphate and $H _2O$ can be separated by the method of filtration.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A mixture of barium sulphate and $H _2O$ can be separated by the method of filtration. Barium sulphate is insoluble in water.  During filtration, barium sulphate remains on the filter paper and water passes as through filter paper as filtrate.

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

A vendor sells white powdered salt-mixed with white powdered stone. The knowledge of which property will help you detect this malpractice?

  1. Ductility

  2. Opacity

  3. Density

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

The purity of the solid salt sample can be anaylsed simply by checking its solubility in proper solvent,

choose a proper solvent and add a pinch of compound to it, if the compound is completely soluble that means compound is pure.

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

What is meant by sublimation?

  1. Conversion of solid into liquid on heating

  2. Conversion of solid into gas on heating

  3. Conversion of liquid into gas on heating

  4. Change of shape of solid on heating
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Sublimation is the transition of a substance directly from the solid to the gas phase without passing through the intermediate liquid phase. Sublimation is easier for volatile materials which can be evaporated at low temperatures.


Hence, the correct option is $B$

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

Sublimation is used to separate :

  1. two liquids having different boiling points

  2. two liquids having same melting point

  3. volatile and non volatile solids

  4. volatile solids having same melting point
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Sublimation is the transition of a substance directly from the solid to the gas phase without passing through the intermediate liquid phase.