Question

Mixing of positively charged colloidal solutions with negatively charged colloidal solution brings …… . The decreasing order of coagulating power of $\mathrm { Na } ^ { + }, \mathrm { Ba } ^ { 2 + }$ and $\mathrm { Al } ^ { 3 + }$ for negatively charged colloidal solutions is ……… .

• A. (a) Mutual coagulations, $\mathrm { Na } ^ { + } > \mathrm { Ba } ^ { 2 + } > \mathrm { Al } ^ { 3 + }$
• A. (b) Mutual coagulation, $\mathrm { Al } ^ { 3 + } > \mathrm { Ba } ^ { 2 + } > \mathrm { Na } ^ { + }$
• A. (c) Coagulation, $\mathrm { Na } ^ { + } > \mathrm { Ba } ^ { 2 + } > \mathrm { Al } ^ { 3 + }$
• A. (d) Peptization, $\mathrm { Al } ^ { 3 + } > \mathrm { Ba } ^ { 2 + } > \mathrm { Na } ^ { + }$

Answer 1

(b)

Sol. According to Hardy Schulze rule, the coagulating power of an ion depends upon its valency. Higher the valency of ion, greater is its coagulating power.