Question

Write whether Fe(OH)₃ sol is a multimolecular or macromolecular colloid.

Answer 1

Fe(OH)₃ sol is a multimolecular colloid. It is made up of a large number of aggregated ferric hydroxide molecules forming colloidal-sized particles. These particles acquire a positive charge because Fe³⁺ ions, which are common to the lattice of Fe(OH)₃, get preferentially adsorbed on their surface. This characteristic aligns with the nature of multimolecular colloids where many small molecules aggregate to form a colloidal particle, distinct from macromolecular colloids which consist of single large molecules spread throughout the dispersion medium.