Test: Types of Colloids (Old NCERT) - JEE MCQ

Depending upon the nature of interaction between the dispersed phase and the dispersion medium, colloidal sols are divided into two categories, namely, lyophilic (solvent attracting) and lyophobic (solvent repelling).

The correct answer is Option D.
In high concentration, particles aggregate to form micelles; it happens above T_k called kraft’s temperature and critical micelle concentration (CMC). If the concentration is low and it forms a true solution.

Foam is a dispersion of a gas in a liquid (liquid foams) or in a solid (solid foams). Foam rubber is gas dispersed in rubber.

The correct answer is Option D.

 

The correct answer is Option C.

Aquadag is the name of a water-based colloidal graphite coating which is a colloidal solution of graphite in water.

The correct answer is Option A
The method of preparation of colloidal solutions of metals such as platinum, gold or silver is known as Bredig's arc method or Electrical disintegration.

 It consists of both dispersion and condensation. It can not be used to prepare a colloidal solution of copper and sodium.

The correct answer is Option B. 

Associated colloids are substances which at low concentrations behave as normal strong electrolytes, but at higher concentrations exhibit colloidal behaviour due to the formation of aggregates. 
The aggregated particles thus formed are called micelles. 
The formation of micelles takes place only above a particular temperature called Kraft temperature (Tk) and above a particular concentration called critical micelle concentration (CMC).

The correct answer is Option A.
Ultracentrifugation involves the separation of colloidal particles from the impurities by centrifugal force.
The impure sol is taken in a tube and the tube is placed in an ultracentrifuge. The tube is rotated at high speeds.
On account of this, the colloidal particles settle down at the bottom of the tube and the impurities remain in the solution.
This solution is termed as centrifugate. The settled colloidal particles are removed from the tube and are mixed with an appropriate dispersing medium. Thus, the pure sol is obtained.

The correct answer is Option A.
AgCl being a covalent molecule is insoluble in water and hence hydrophobic.
 

The correct answer is Option A.

Blood is a colloidal which contains crystalloids as impurity hence can be separated by Dialysis.