The cotterells precipitator is used to :

1. neutralize charge on carbon particles in air in smoke

2. coagulate carbon atoms of smoke

3. bring in cataphoresis in carbon particles

4. all of the above

Which ion is adsorbed when a diluted aqueous solution of AgNO₃ (excess) is added to KI solution, resulting in formation of positively charged sol particles of AgI?

1. K⁺

2. Ag⁺

3. I^-

4. NO₃^-

The phenomenon in which adsorption and absorption takes place simultaneously is called:

1. Desorption                       

2. Sorption

3. Both 1 and 2              

4. None of these

Gas masks containing activated charcoal remove poisonous gases from the atmosphere, and act on the principle of:

1. Adsorption

2. Absorption

3. Sorption

4. All of these

Chemisorption is:

1. multimolecular in nature

2. reversible

3. often highly specific and directional

4. not very specific