Question

Hardening of lather in tanning is based on:
A) Electrophoresis
B) Electro-osmosis
C) Mutual coagulation
D) Persistent dialysis

Answer 1

In order to solve this question we should know about the definition of the process which is required for special purpose accurately. Such as the tanning industry, hardening of lather by the process of mutual coagulation.

Complete answer:
For solving this first we should know tanning so tanning is the process of treating skins and hides of animals to produce lather. Tanning hide into leather involves a process which permanently alters the protein structure of skin which makes it more durable and less susceptible to decomposition, and also possibly coloring it.
In simple words we can say that coagulation of chemicals of opposite charges is known as tannin.
As it is mentioned in the question we have to tannin the lather which we know that it is positively charged so in order to coagulate it we want the colloidal chemical which is negatively charged.
When the negatively charged chemical ions are put on lather these are soaked by the lather and by here the process starts. This is known as mutual coagulation.
After it when the negatively colloidal charged particles and positively charged particles mixed up with this coagulation results in the hardening of the lather.
So after the above discussion we can say that the hardening of lather in the tanning industry is due to mutual coagulation of charges.
Hence, option (C) is correct.

Note: Mutual coagulation is the process of destabilization of colloids by neutralizing electric charge of dispersed phase particles which result in the aggregation of the particle. It should be kept in mind if it becomes too hard then it will lead to brittle failure, so the hardening process should be upto optimum condition.