Tanning of leather is:

1. coloring of leather by chemicals

2. drying process to make the leather hard

3. polishing of leather to make it look attractive

4. coagulative hardening of the leather by chemicals

When sulphur sol is evaporated solid sulphur is left. On mixing with water no colloidal sol is formed. Sulphur sol is: 

1. hydrophilic

2. hydrophobic

3. reversible

4. lyophilic

The Critical Micelle Concentration (CMC) is:

1. The concentration at which micellization starts

2. The concentration at which true solution is formed

3. The concentration at which one molar electrolyte is present per 1000 g of solution

4. The concentration at which solute and solution from equilibrium

What is a solution that isn't a lyophilic colloid?

1. Milk

2. Gum

3. Fog

4. Blood

An example of intrinsic colloid is:

1. As₂S₃ sol                         

2. Fe(OH)₃ sol

3. egg albumin                     

4. Au sol

Tails of comets are visible due to:

1. Tyndall effect

2. Reflection

3. Brownian motion

4. None of the above

Bleeding is stoped by the application of ferric chloride. This is because :

1. the blood starts flowing in the opposite direction

2. the blood reacts and a solid is formed which seals the blood vessel

3. the blood is coagulated and the blood vessel are sealed

4. the ferric chloride seals the blood vessel

A dust storm is:

1. Dispersion of solid in gas

2. Dispersion of a gas in solid

3. Dispersion of solid in solid

4. Dispersion of a gas in liquid

Medicines are more effective if they are used in:

1. Colloidal state

2. Solid-state

3. Solution state

4. None of the above 

Hydrolysis of cane-sugar is catalysed by:

1. H⁺                         

2. mineral acids

3. enzymes                 

4. all of these