On addition of 1 mL solution of 10% NaCl to 10 mL gold solution in the presence of 0.025 g of starch, the coagulation is prevented because starch has the following gold numbers :

• 25

• 0.025

• 0.25

• 2.5

When a beam of light is passed through a colloidal solution it :

• is reflected

• is scattered

• transmitted

• absorbed

The coagulating power of an electrolyte for arsenious sulphide decreases in the order :

• Na⁺ > Al³⁺ > Ba²⁺

• PO${}_4^{3-}$ > SO${}_4^{2-}$ > Cl^-

• Cl > SO${}_4^{2-}$ > PO${}_4^{3-}$

• Al³⁺ > Ba²⁺ > Na⁺

Colligative properties are used for the determination of :

• molar mass

• equivalent weight

• arrangement of molecules

• melting point and boiling point

Sulphur colloid prepared by

• mechanical dispersion

• oxidation

• electrical dispersion

• reduction

Colour of colloids depends on which of the following factors ?

• Size

• Mass

• Charge

• Nature

Which one of the following reactions is an example of heterogeneous catalysis?

• 2CO (g) + O₂ (g) $\stackrel{\mathrm{NO} \left(\mathrm{g}\right)}{\to }$ 3CO₂

• 2SO₂ (g) + O₂ (g) $\stackrel{\mathrm{NO} \left(\mathrm{g}\right)}{\to }$ 2SO₃

• 2CO (g) + O₂ (g) $\stackrel{\mathrm{Pt} \left(\mathrm{s}\right)}{\to }$ 2CO₂

• CH₃CHO (g) $\stackrel{{\mathrm{I}}_2 \left(\mathrm{g}\right)}{\to }$ CH₄ + CO

Cod liver oil is

• an emulsion

• solution

• colloidal solution

• suspension

Paste is

• suspension of solid in a liquid

• mechanical dispersion of a solid in liquid

• colloidal solution of a solid in solid

• None of the above

The equation for Freundlich adsorption isotherm is

• x/m =kp^1/n

• x= mkp^1/n

• x/m= kp^-n

• All of these