A negatively charged suspension of clay in water needs for precipitation the minimum amount of:

(a) aluminium chloride

(b)potassium sulphate

(c)sodium hydroxide

(d)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 which:

(1) Homogenesis the emulsion

(2) Stabliizes the emulsion

(3) Retards the dispersion of liquid in liquid

(4) Coagulates the emulsion

Flocculation value is expressed in terms of:

(a) millimole per litre

(b) mole per litre

(c) gram per litre

(d) mole per millilitre

Which is an emulsifier?

(1) Soap

(2) Oil

(3) NaCl

(4) Water

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

(1) It's shape

(2) Amount of its charge

(3) The sign of charge

(4) Both amount and sign of the charge

Lyophobic collloids are:

(1)reversible colloids

(2)irreversible colloids

(3)protective colloids

(4)gum, proteins

The decomposition of H₂O₂ may be checked by adding a small quantity of phosphoric acid. This is an example of:

(a) neutralization           (b) negative catalysis

(c) positive catalysis       (d) catalytic poisoning

Which of the following is not applicable to chemisorption?

1. Its heat of adsorption is high

2. It takes place at high temperature

3. It is reversible

4. It forms unimolecular layer

As₂S₃ sol is

1. possible colloid                 2. negative colloid

3. neutral colloid                  4. none of the above