Among the given options, which element is the minimum required for precipitation of a negatively charged suspension of clay in water?

1. Aluminium chloride.

2. Potassium sulphate.

3. Sodium hydroxide.

4. Hydrochloric acid.

The arsenious sulphide sol has negative charge. The maximum coagulationg power for precipitating it is of :

1. 0.1 N Zn(NO₃)₂

2. 0.1 N Na₃PO₄

3. 0.1 N ZnSO₂

4. 0.1 N AlCl₃

An emulsifier is a substance that:

1. Homogenesis the emulsion

2. Stabilizes the emulsion

3. Retards the dispersion of liquid in the liquid

4. Coagulates the emulsion

What is a colloidal solution that is commonly used to treat skin diseases?

1. Colloidal sulphur.                   

2. Colloidal silver.

3. Colloidal gold.                         

4. Colloidal antimony.

Adsorption is accompanied by:

1. decrease in entropy of the system

2. decrease in enthalpy of the system

3. T$∆$S for the process is negative

4. all of the above

How is the flocculation value expressed?

1. Millimole per litre.

2. Mole per litre.

3. Gram per litre.

4. Mole per millilitre.

A liquid which makes scatters a beam of light (visible in a dark room) but leaves no residue when passed through a filter paper is best described as:

1. A suspension

2. Sol

3. True solution

4. None of the above

Which is an emulsifier?

1. Soap

2. Oil

3. NaCl

4. Water

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.

The capacity of an ion to coagulate a colloidal solution depends on:

1. its shape

2. amount of its charge

3. the sign of charge

4. both amount and sign of the charge