The stability of a lyophobic colloid is due to

• adsorption of covalent molecules on the colloid

• the size of the particles

• the charge on the particles

• Tyndall effect

102.

Which of the following cations will have minimum flocculation value for arsenic sulphide sol?

• Na⁺

• Mg²⁺

• Ca²⁺

• Al³⁺

Adsorption theory is applicable for

• homogeneous catalysis

• heterogeneous catalysis

• autocataylsis

• induced catalysis

All colloidal dispersions have

• low osmotic pressure

• no osmotic pressure

• high osmotic pressure

• very high osmotic pressure

Silver iodide is used for producing artificial rain because AgI

• is easy to synthesize

• has crystal structure similar to ice

• is insoluble in water

• is easy to spray at high altitude

During the adsorption of a gas on the surface of a solid, which of the following is true?

• $∆\mathrm{G} > 0, ∆\mathrm{H} < 0, ∆\mathrm{S} < 0$

• $∆\mathrm{G} < 0, ∆\mathrm{H} < 0, ∆\mathrm{S} < 0$

• $∆\mathrm{G} <\hspace{0.17em}0, ∆\mathrm{H} < 0, ∆\mathrm{S} > 0$

• $∆\mathrm{G} <\hspace{0.17em}0, ∆\mathrm{H} > 0, ∆\mathrm{S} < 0$

A crystalline solid X reacts with dil. HCl to liberate a gas Y. Y decolourises acidified KMnO₄. When a gas 'Z' is slowly passed into an aqueous solution of Y, colloidal sulphur is obtained X and Z could be respectively

• Na₂S, SO₃

• Na₂SO₄, H₂S

• Na₂SO₃, H₂S

• Na₂SO₄, SO₂

Gold sol is not

• a macromolecular colloid

• a lyophobic colloid

• a multimolecular colloid

• negatively charged colloid

For Freundlich isotherm a graph of log x/m is plotted against log p. The slope of the line and its y-axis intercept, respectively corresponds to

• $\frac{\mathit{1}}{n} ,\mathit{ }k$

• $\log \frac{1}{n} , k$

• $\frac{1}{n} , \log k$

• $\log \frac{1}{\mathrm{n}}, \log \mathrm{k}$

The electrolyte having maximum flocculation value for AgI/Ag⁺ sol is

• NaCl

• Na₂S

• Na₂SO₄

• Na₃PO₄