Which is an emulsifier?

1. Soap

2. Oil

3. NaCl

4. Water

KClO₃ on heating decomposes into KCl and O₂. If some MnO₂ is added, the reaction goes much faster because:

1. MnO₂ decomposes to give oxygen.

2. MnO₂ provides  heat by reacting.

3. Better contact is provided by MnO₂

4. MnO₂ acts as a catalyst.

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

1. its shape

2. amount of its charge

3. the sign of charge

4. both amount and sign of the charge

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

Which statement about enzymes is not correct?

1. Enzymes are in colloidal state

2. Enzymes are catalysts

3. Enzymes can catalyse any reaction

4. Urease is an enzyme

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

1. promoter                       

2. poison

3. auto-catalyst                 

4. none of these

Gold number:

1. may be defined as the milligram of the dry material of which the hydropholic sol is prepared and which when added to 10 mL of red gold sol, will prevent it from coagulation on the addition of 1mL of 10 percent sodium chloride solution.

2. may be defined as the milligram of the dry material of which the hydrophilic sol is prepared and which when added to 1 mL of red gold sol will prevent it from coagulation on the addition of 10 mL of 10 percent sodium chloride solution.

3. may be defined as the miligram of the dry material of which the hydrophilic sol is prepared and which when added to 1 mL of red gold sol will prevent it from coagulation on the addition of 1 mL of 1 percent sodium chloride solution

4. none of the above 

A liquid which makes scatters a beam of light (visible in a dark room) but leaves no residue when passed through a filter paper is best described as:

1. A suspension

2. Sol

3. True solution

4. None of the above