Question
Mixing of positively charged colloidal solution with negatively charged colloidal solution brings _________. The decreasing order of coagulating power of $$N{a^ + },B{a^{2 + }}$$ and $$A{l^{3 + }}$$ for negatively charged colloidal solution is __________.
A.
mutuaI coagulation, $$N{a^ + } > B{a^{2 + }} > A{l^{3 + }}$$
B.
mutual coagulation, $$A{l^{3 + }} > B{a^{2 + }} > N{a^ + }$$
C.
peptization, $$N{a^ + } > B{a^{2 + }} > A{l^{3 + }}$$
D.
peptization, $$A{l^{3 + }} > B{a^{2 + }} > N{a^ + }$$
Answer :
mutual coagulation, $$A{l^{3 + }} > B{a^{2 + }} > N{a^ + }$$
Solution :
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.