Key Concepts in Solutions and Separation Techniques

Steps:

• Define saturated solution: maximum solute dissolved in a given solvent at a specific temperature.
• Define solution: homogeneous mixture of solute and solvent, not a chemical reaction product.
• Define filtration: process separating solid residue on filter from liquid filtrate passing through.
• Define distillation: vaporization and condensation separating components, leaving non-volatile residue in flask.

Why D is correct:

• In distillation, the non-volatile substance left in the heated flask after volatile parts are removed is defined as the residue.

Why the others are wrong:

• A: Saturated solution has maximum solute in solvent, not solvent in solute.
• B: Solution is a mixture, not a compound from solute-solvent reaction.
• C: Filtrate is the liquid passing through filter; residue remains on paper.

Final answer: D