Tag: chemistry

Questions Related to chemistry

All heterogeneous catalysts are based on the process of adsorption

applications of adsorption adsorption adsorption and colloids surface chemistry chemistry

  1. True

  2. False

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Correct Option: A
Explanation:

Heterogeneous catalysts are materials capable of adsorbing liquids and gasses on their surface. Hence, they are based on the process of adsorption.

Dyes like cosin and fluorescein are used as indicator in titrating bromide solution with $ZnSO _4$

applications of adsorption adsorption adsorption and colloids surface chemistry chemistry

  1. True

  2. False

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Correct Option: A
Explanation:

True dyes like cosin and fluorescein are used as indicator in titrating bromibe solution with zinc sulphate.

For purification of tincture of alkaloids from pigments before determination of their alkaloidal content, adsorption column chromatography has been used for separation and purification of the Alkaloids of Atropa Belladonna from the bulk of non- alkaloidal matter present in alumina columns.

applications of adsorption adsorption adsorption and colloids surface chemistry chemistry

  1. True

  2. False

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Correct Option: A
Explanation:

Adsorption Chromatography with alumina as the adsorbent may be used for the separation and purification of the Alkaloids of Atropa Belladonna from the bulk of non- alkaloidal matter present in alumina columns, whereas tincture prepared by the percolation process in adsorption column chromatography.

Silical gel is commonly used as:

applications of adsorption adsorption adsorption and colloids surface chemistry chemistry

  1. wetting agent

  2. drying agent

  3. solvent

  4. catalyst

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Correct Option: B
Explanation:

Silica gel is commonly used as a drying agent as it adsorb moisture on its surface to prevent growth of microorganism and foul smelling.

Which of the following gases is adsorbed most by activated charcoal?

applications of adsorption adsorption adsorption and colloids surface chemistry chemistry

  1. $CO _2$

  2. $N _2$

  3. $CH _4$

  4. $H _2$

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Correct Option: A
Explanation:

     Easily liquefiable gases can adsorb more than the other gases.

As $CO _2$ is an easily liquefiable gas, hence it is adsorbed more by charcoal.

Which of the following is/are true statement(s)?

applications of adsorption adsorption adsorption and colloids surface chemistry chemistry

  1. Water vapour is absorbed by anhydrous calcium chloride while it is adsorbed by silica gel.

  2. $NH _3$ is absorbed by water but adsorbed by charcoal.

  3. Sugar is decolourized by animal charcoal based on adsorption.

  4. Water is absorbed by conc. $H _2SO _4$.

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Correct Option: A,B,C,D
Explanation:

Adsorption is the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface. This process creates a film of the adsorbate on the surface of the adsorbent.
Absorption is a physical or chemical phenomenon or a process in which atoms, molecules or ions enter some bulk phase – gas, liquid or solid material.

a) Water vapour is absorbed by anhydrous calcium chloride while it is adsorbed by silica gel.
b) Ammonia is absorbed by water but adsorbed by charcoal.
c) Decolourisation of sugar solution by activated charcoal is another example of adsorption. Charcoal absorbs the colouring material and thus decolourising the solution.
d) Water is absorbed by sulphuric acid because both are in same phase.
NHis absorbed by water but adsorbed by charcoal.

Which of the following can adsorb largest volume of hydrogen gas?

applications of adsorption adsorption adsorption and colloids surface chemistry chemistry

  1. Finely divided platinum

  2. Finely divided nickel

  3. Colloidal solution of palladium

  4. Colloidal Hydroxide

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Correct Option: C
Explanation:

Colloidal solution of palladium can adsorb largest volume of hydrogen gas as the surface area of palladium is maximum in its colloidal solution. Higher is the surface area of catalyst, larger will be the volume of hydrogen adsorbed.

Application of adsorption is/are :

applications of adsorption adsorption adsorption and colloids surface chemistry chemistry

  1. For desiccation or dehumidification

  2. Heterogeneous catalysts

  3. For both heterogenous catalysts and for desiccation or dehumidification

  4. None of the above

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Correct Option: C
Explanation:

Applications of adsorption are :

1.Charcoal is used as a decoloriser as it adsorbs the coloring matter from the coloured solution of sugar.

2. Silica gel adsorbs moisture from the desiccators.

3. Silica and alumina gels are used as adsorbents for removing moisture and for controlling humidity of rooms.

4. Activated charcoal is used in gas masks as it adsorbs all the toxic gases and vapours and purifies the air for breathing.

5 .Adsorption processes are useful in carrying out heterogeneous catalysis.

Activated charcoal is used in gas masks to remove poisonous gases.

applications of adsorption adsorption adsorption and colloids surface chemistry chemistry

  1. True

  2. False

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Correct Option: A
Explanation:

Activated charcoal adsorps poisonous gas thus used in the gas masks.

Application of adsorption in pharmacy and allied field is/are :

applications of adsorption adsorption adsorption and colloids surface chemistry chemistry

  1. Decolourising agents

  2. Adsorption chromatography

  3. Purified talc

  4. None of the above

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Correct Option: A,B
Explanation:

Application of adsorption in pharmacy and allied fields are Decolourising agents, adsorption chromatography.