Question

How does the addition of electrolytes cause coagulation?

Answer 1

Coagulation:

• The process of becoming viscous or thickened into a coherent mass is known as coagulation.
• When an electrolyte is added to sol, the colloidal particles take up ions carrying opposite charges from the electrolyte.
• Therefore, their charge gets neutralized, and thus the uncharged, particles come closer and get coagulated.
• The coagulating power of an ion depends on both the sign and magnitude of the charge on the ion.
• The ions of the opposite sign of the charge to those present on the surface of the particles cause the precipitation of the particles.
• Thus, the positively charged ions of the electrolyte will coagulate with negatively charged particles.
• Like this, the negatively charged ions of the electrolyte will coagulate with the positively charged particles.
• It depends upon the valency of the active ion is called a flocculating ion, which is an ion-carrying charge opposite to the charge on the colloidal particles.