Question

Coagulation of colloids can be achieved by:

• A. centrifugation
• B. adding electrolyte
• C. change in $pH$
• D. adding water

Answer 1

Answer: (A), (B), (C)

The correct options are
A centrifugation
B adding electrolyte
C change in $pH$

Stability of the lyophobic sols is due to presence of charge on colloidal particles. If charge is removed, particles come together and settle down. Spontaneous destabilization of solution is ageing and destabilization of solution by artificial means is called coagulation.
Methods of coagulation
By boiling
By dialysis
By addition of electrolytes
By mixing two oppositley charged sols
By electrophoresis.