Gels are broadly categorized based on their rheological and hydration properties into elastic and no — Surface Chemistry Chemistry Question

💡 Solution & Explanation

Elastic (reversible) gels include gelatin, agar-agar, and starch; they can absorb water and swell (imbibition). Non-elastic (irreversible, rigid) gels strictly include silica gel, alumina gel, and ferric hydroxide gel. From the given list, only silica gel and ferric hydroxide gel are non-elastic. The count is 2.