Which of the following best indicates that a solution is saturated?

• A. No more solute dissolves and excess solute remains undissolved at the bottom.
• B. The temperature of the solution increases.
• C. All of the solute dissolves completely.
• D. The solution becomes colorless.

Answer: (A)

Verified step by step guidance

1. Understand the concept of a saturated solution: it is a solution in which the maximum amount of solute has dissolved at a given temperature and pressure, and no more solute can dissolve.
2. Recognize that when a solution is saturated, any additional solute added will not dissolve and will remain as undissolved solid at the bottom of the container.
3. Note that if the temperature of the solution increases, it may affect solubility but does not directly indicate saturation by itself.
4. Understand that if all the solute dissolves completely, the solution is unsaturated, meaning it can still dissolve more solute.
5. Realize that the solution becoming colorless is not a reliable indicator of saturation, as color depends on the nature of the solute and solvent, not saturation status.