What results are obtained from adding FeCl₃ to K₄[Fe(CN)₆] in a diluted, cold solution?

1. Prussian blue sol.                     

2. Fe₄[Fe(CN)₆]₃ sol.

3. Positive sol.                               

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.

Which is an emulsifier?

1. Soap

2. Oil

3. NaCl

4. Water

The blue colour of the water of the sea is due to :

1. refraction of the blue light by the imputities in sea water

2. reflection of blue light by sea water

3. scattering of blue light by sol particles

4. absorption of other colours except the blue colour by water molecules

What does blood contain?

1. Positively charged particles.

2. Negatively charged particles.

3. Neutral particles.

4. Negatively as well as positively charged particles.

Lyophobic colloids are:

1. Reversible colloids

2. Irreversible colloids

3. Protective colloids

4. Gum, and proteins

BaSO₄ acts as.... for Pd in Rosenmund's reaction:

1. promoter                       

2. poison

3. auto-catalyst                 

4. none of these

What does the name "aquadag" refer to?

1. Cu in water sol.

2. Pt in water sol.

3. Graphite in water sol.

4. None of the above.

Hydrolysis of cane-sugar is catalysed by:

1. H⁺                         

2. mineral acids

3. enzymes                 

4. all of these

Medicines are more effective if they are used in:

1. Colloidal state

2. Solid-state

3. Solution state

4. None of the above