Question

Explain the difference between pH dependent surface charge and the surface charge produced by isomorphic substitution in clay minerals?

Answer 1

Answer:

Clay particles will have negative charge which helps in attracting molecules.

Positively charged particles are called as cations.

Negitively charged particles are called as Anions.

pH Dependent surface charge

pH dependent charge is the charge/property which depends up on the pH of the solution mixed with clays and leads to release of H+ ions.

isomorphic substitution

Clay minerals structure which is present in a substance will be replaced by alluminum which actually consists silica

Difference

Main difference between this pH dependent surface charge and isomorphic substitution is that

pH dependent process which require sand works with help of solutions with certain pH value but in isomorphic substitution which require substitution of metals.

The surface charge due to pH depndende process is assumed as result only from absorption of H+ and OH- ions

Where in isomorphic charged substance the charge produced by the substance will balanced by positive charge ions with out changing the crystal structure of mineral.