Milk contains a protein that is very good for health. The protein is:

(a) caffeine

(b) calciferol

(c) keratin

(d) casein

The charge on As₂S₃ sol is due to the adsorption of:

(1) H⁺                             

(2) OH^-

(3) ${\mathrm{O}}_2^{-}$                             

(4) S^2-

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

(a) BaSO₄

(b) Quiniline

(c) Both (a) and (b)

(d) None of these

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 to remove poisonous gases from atmosphere acts on the principle of:

(1) Adsorption

(2) Absorption

(3) Sorption

(4) All of these

Tanning of leather is:

(1) Colouring 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: 

(a)hydrophilic

(b)hydrophobic

(c)reversible

(d)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

Hardy-Schulze rule states that:

(1) Non-electrolytes have better coagulating action on colloids than electrolytes.

(2) Sols are coagulated by effective ions whose charge is opposite to that of sol and the ions of higher charge are much more effective than the ions of lower charge.

(3) Charge of the ions has no effect on the coagulation of a sol.

(4) Sols are coagulated only by those ions whose charge is similar to that of the sol.

An example of intrinsic colloid is:

(a) As₂S₃ sol                         (b) Fe(OH)₃ sol

(c) egg albumin                      (d) Au sol