$1$ $\mathrm{mol}$ of $\left[\mathrm{AgI}\right]{\mathrm{I}}^{-}$ can be coagulated by - 

1. 1 mol of Pb(NO₃)₂                          

2. \(\frac{1}{2}\) mol of Pb(NO₃)₂

3. \(\frac{2}{3}\) mol of Pb(NO₃)₂                           

4. None of the above.

The process of converting precipitate into collidal solution on adding an electrolyte is called:

(1) Peptisation                             

(2) Dialysis

(3) Electro-osmosis                     

(4) Eelectrophoresis

Assertion: Physical and chemical adsorption respond differently to a rise in temperature.

Reason: Chemical adsorption requires some activation energy.

Assertion : Catalyst in general, in the form of finely divided powder.

Reason : Finer is the particle of a solid, greater is its surface area.

Assertion : The addition of ferric hydroxide sol to arsenic sulphide sol results in the precipitation

                   of both.

Reson : The colloidal particles in ferric hydroxide carry positive charge, whereas those in arsenic

             sulphide sol carry negative charge.

Assertion: Lowering of temperature, increases the rate of physisorption.

Reason: Adsorption increases with an increase in temperature.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Colloids can be prepared by 

1. Tyndall Effect                      

2.  Electrophoresis

3.  Dialysis                             

4.  Peptization

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

In an adsorption experiment, a graph between log(x/m) versus log P was found to be linear with a slope of 45$°$. The intercept on the y-axis was found to be 0.3. What will be the value of x/m at a pressure of 3 atm for the Freundlich adsorption isotherm when 1/n remains constant?

[Antilog 0.3 = 2]

1.  2

2.  4

3.  6

4.  5

Which of the following reactions leads to the formation of a substance in colloidal state?

(A) $2{\mathrm{HNO}}_3+3{\mathrm{H}}_2\mathrm{S}\stackrel{ }{\to }3\mathrm{S}+3{\mathrm{H}}_2\mathrm{O}+2\mathrm{NO}$

(B) ${\mathrm{SnCl}}_2+{\mathrm{HgCl}}_2\stackrel{ }{\to }{\mathrm{SnCl}}_4+\mathrm{Hg}$

(C) $2\mathrm{Mg}+{\mathrm{CO}}_2\stackrel{ }{\to }2\mathrm{MgO}+\mathrm{C}$

(D) $\mathrm{Cu}+{\mathrm{CuCl}}_2\stackrel{ \mathrm{HCl} }{\to }{\mathrm{Cu}}_2{\mathrm{Cl}}_2$