Define the following: (i) Peptization (ii) Reversible sols

[Hint : Mutual precipitation/coagulation took place.]

(i) Lyophilic sols: Colloidal sols that are formed by mixing substances such as gum, gelatin, starch, etc. with a suitable liquid (dispersion medium) are called lyophilic sols. These sols are reversible...

Lyophilic sols: Lyophilic sols are those sols in which the particles of dispersed phase have great affinity for the dispersion medium, e.g., sols of gum, gelatine, starch, etc.   Lyophobic sols:...

(c) : According to Gibb's formula, ΔG = ΔH – TΔS Since ΔH and ΔS, both are +ve, for ΔG < 0, the value of T > Te.

The colloidal particles bear similar electric charge and that is why they stay away from each other due to repulsion. If the charge is removed, they come together and are...

(i) Micelles: There are some substances which at low concentration behave as normal strong electrolytes but at higher concentration exhibit colloidal behaviour due to formation of aggregated particles. The aggregated...

The process of settling of colloidal particles through induced aggregation by the addition of some suitable electrolyte is known as coagulation. Three methods by which coagulation of lyophobic sols can...

(a)and (d) : Reversible ;  (b) and (c ): Irreversible. 

∆S = q rev/T

(d) 1.44 × 10-5 / (0.082 × 773)-2