Topic: Surface Chemistry (Test 5)



Topic: Surface Chemistry
Q.1
Liquid – liquid solutions are known as
A. Gel
B. Foam
C. Aerosols
D. Emulsions
Answer : Option D
Explaination / Solution:

Dispersed phase and dispersion medium both are liquids.

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Q.2
Flocculation value is expressed in terms of
A. Millimoles/liter
B. Grams/liter
C. Moles/liter
D. Moles/millilitre
Answer : Option A
Explaination / Solution:

Fact

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Q.3
In aerosol the dispersion medium is
A. Solid
B. None of these
C. Gas
D. Liquid
Answer : Option C
Explaination / Solution:

Dispersion medium is gas.

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Q.4
Enzymes are
A. Substances made by chemists to activate washing powder
B. Catalyst found in organisms
C. Synthetic catalyst
D. Very active vegetable catalyst
Answer : Option B
Explaination / Solution:

Enzymes are biological catalyst, they catalize different chemical reactions in body.

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Q.5
A biochemical catalyst is
A. Nitrogen molecule
B. A carbohydrates
C. An enzyme
D. An amino acid
Answer : Option C
Explaination / Solution:

Enzymes are biological catalyst, they catalize different chemical reactions in body.

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Q.6
The number of phases in colloidal system are
A. Two
B. Four
C. One
D. Three
Answer : Option A
Explaination / Solution:

Dispersed phase, dispersion medium

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Q.7
The process of separation of colloids by passing through semi permeable membrane is called
A. Electrophoresis
B. Filtration
C. Dialysis|
D. Ultrafilteration
Answer : Option C
Explaination / Solution:

Dialysis we use, salt solution of approximately same concentration outside the artificial blood capillary, so that urea comes out of the blood, but other useful substances like NaCl , blood cell etc does not. Blood is a colloid.

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Q.8
Liquid – liquid sols are known as
A. Foam
B. Emulsions
C. Gels
D. Aerosols
Answer : Option B
Explaination / Solution:

Liquid in liquid sols are emulsions

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Q.9
Whipped cream is an example of
A. Solid emulsion
B. Suspension
C. Lyophilic sol
D. Foam
Answer : Option D
Explaination / Solution:

Whipped cream is example of foam.

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Q.10
Which among the following substances is an example of multimolecular colloids?
A. Sulphur sol
B. Micelles
C. Starch sol
D. Polystyrene
Answer : Option A
Explaination / Solution:

Multimolecular colloids are formed when a large number of atoms or molecules of a substance aggregate together to form speices having size in colloidal range. sulphur sol contains a thousand of S8 molecules.

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