Peptization is the process of?

1. Precipitating colloidal particles.

2. Purifying colloidal particles.

3. Dispersing the precipitate into a colloidal state.

4. None of the above.

Which acts as poison for Pd-charcoal in lindlar's catalyst ?

1. BaSO₄

2. Quiniline

3. Both 1. and 2.

4. None of these

Which is the electrolyte that is least effective in causing coagulation of +ve ferric hydroxide sol?

1. KBr

2. K₂SO₄

3. K₂CrO₄

4. K₃[Fe(CN)₆]

Platinized asbestos used as a catalyst in the manufacture of H₂SO₄ is an example of:

1. heterogeneous catalyst                   

2. auto-catalyst

3. homo-catalyst                                 

4. induced catalyst

In a reversible reaction, a catalyst:

1. increases the rate of the forward reaction only

2. increases the rate of the forward reaction to a greater extent than that of  the backward reaction

3. increases the rate of the forward reaction and decreases that of the backward reaction to the different extent

4. increases the rate of the forward and backward reactions equally

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

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

In adding 1 mL of solution of 10 % NaCl to 10 mL of gold solution in the presence of 0.25 g of starch, the coagulation is just prevented. Starch has a gold number equal to:

1. 0.25                     

2. 2.5

3. 250                     

4. 0.025