Peptisation is a process used to convert precipitates into colloidal solutions. This process involves the breaking down of larger particles (precipitate) into smaller particles, which are then dispersed in a solvent, forming a colloidal solution. This process typically uses a stabilising agent (called a peptising agent) to prevent the colloidal particles from aggregating. Option (A) colloid: Correct. Peptisation results in the formation of a colloidal solution from a precipitate. Option (B) precipitate: Incorrect. A precipitate is formed when a substance falls out of solution, not during peptisation. Option (C) peptide: Incorrect. Peptisation does not form peptides; it forms colloidal particles. Option (D) solution: Incorrect. Peptisation specifically forms a colloidal solution, not just a simple solution. Thus, the correct answer is (A) colloid.
