Water vapours can be both adsorbed and absorbed by respectively ?

1. Silica gel and ${\mathrm{CaCl}}_2$

2. Chalk and ${\mathrm{CaCl}}_2$

3. ${\mathrm{CaCl}}_2$ and Silica gel

4. ${\mathrm{CaCl}}_2$ and Chalk

The characteristics associated with adsorption are:

1. ∆G, ∆H, and ∆S are all negative.
2. ∆G and ∆H are negative, but ∆S is positive.
3. ∆G and ∆S are negative, but ∆H is positive.
4. ∆G is negative, but ∆H and ∆S are positive.

In the Freundlich adsorption isotherm, the value of 1/n is:
1. Between 0 and 1 in all cases.
2. Between 2 and 4 in all cases.
3. 1 in the case of physical adsorption.
4. 1 in the case of chemisorption.

Which mixture of the solutions will lead to the formation of a negatively charged colloidal [AgI]I^- sol?

1. 50 mL of 0.1 M AgNO₃ + 50 mL of 0.1 M KI

2. 50 mL of 1 M AgNO₃ + 50 mL of 0.5 M KI

3. 50 mL of 1 M AgNO₃ + 50 mL of 2 M KI

4. 50 mL of 2 M AgNO₃ + 50 mL of 1.5 M KI

The equation that represents a Freundlich adsorption isotherm is: 

1. $\frac{x}{m}=k{p}^{0.3}$

2. $\frac{x}{m}=k{p}^{2.5}$

3. $\frac{x}{m}=k{p}^{-0.5}$

4. $\frac{x}{m}=k{p}^{-1}$

The coagulating power of electrolytes with ions Na⁺,  Al³⁺, and Ba²⁺${ rise }^{}$for arsenic sulphide sol increases in the order :

1. $A{l}^{3+ }< B{a}^{2+ }< N{a}^{+}$

2. $N{a}^{+ }< B{a}^{2+ }< A{l}^{3+}$

3. $B{a}^{2+ }< N{a}^{+ }< A{l}^{3+}$

4. $A{l}^{3+ }< N{a}^{+ }< B{a}^{2+}$

KClO₃ on heating decomposes into KCl and O₂. If some MnO₂ is added, the reaction goes much faster because:

1. MnO₂ decomposes to give oxygen.

2. MnO₂ provides  heat by reacting.

3. Better contact is provided by MnO₂

4. MnO₂ acts as a catalyst.

Which of the following electrolytes, Na₂SO₄, CaCl₂, Al₂(SO₄)₃, and NH₄Cl, is the most effective coagulating agent for Sb₂S₃ sol?

1. Na₂SO₄                             

2. CaCl₂

3. Al₂(SO₄)₃                           

4. NH₄Cl

The surface tension of lyophilic sols is:

1. Lower than H₂O

2. More than H₂O

3. Equal to H₂O

4. None of the above.