An emulsion cannot be broken by ............. and ................

1. Heating.

2. Adding more amount of dispersion medium.

3. Freezing.

4. Centrifugation

Substances among the following that can precipitate the negatively charged emulsions are-

a.  KCI

b.  Glucose

c.  Urea

d.  NaCl

1. (a, b)

2. (b, c)

3. (c, d)

4. (a, d)

Colloids among the following that cannot be coagulated easily is -

a.  Lyophobic colloids

b.  Irreversible colloids

c. Reversible colloids

d.  Lyophilic colloids

1. (a, b)
2. (b, c)
3. (c, d)
4. (a, d)

The correct statements regarding the situation, when a Lyophilic sol is added to a Lyophobic sol, are-

a. Lyophobic sol is protected

b. Lyophilic sol is protected

c. Film of lyophilic sol is formed over lyophobic sol

d. Film of lyophobic sol is formed over lyophilic sol

1. (a, b)

2. (b, c)

3. (c, a)

4. (a, d)

Phenomenon that occurs when an electric field is applied to a colloidal solution and electrophoresis is prevented-

a.  Reverse osmosis takes place

b.  Electroosmosis takes place

c.  Dispersion medium begins to move

d. Dispersion medium becomes stationary

The correct choice among the given is -

1. (a, b)
2. (b, c)
3. (c, d)
4. (a, d)

The correct statement regarding changes in the catalyst during a reaction is -

a.  Physical

b.  Qualitative

c.  Chemical

d.  Quantitative

1. (a, b)
2. (b, c)
3. (c, d)
4. (a, d)

Physical adsorption of a gaseous species may change to chemical adsorption with ..........

1.  Decrease in temperature.

2.  Increase in temperature.

3.  Increase in surface area of adsorbent.

4.  Decrease in surface area of adsorbent.

In physisorption adsorbent does not show specificity for any particular gas because..........

1.  Involved van der Waals’ forces are universal.

2.  Gases involved behave like ideal gases.

3.  Enthalpy of adsorption is low.

4.  It is a reversible process.

Among the following options the example of absorption is :

1.  Water on silica gel.

2.  Water on calcium chloride.

3.  Hydrogen on finely divided nickel.

4.  Oxygen on metal surface.

On the basis of the data given below, the gas which shows the least adsorption on a definite amount of charcoal is-

1. CO₂
2. SO₂
3. CH₄
4. H₂