State whether each of the following refers to a saturated or an unsaturated solution:
a. A crystal added to a solution does not change in size.

Verified step by step guidance

1. Understand the definitions: A saturated solution contains the maximum amount of solute that can dissolve at a given temperature, meaning it is in equilibrium with undissolved solute. An unsaturated solution can still dissolve more solute.
2. Analyze the scenario: When a crystal is added to a solution and does not change in size, it indicates that the solution is already at equilibrium with the solute.
3. Relate this observation to the concept of saturation: If the solution is at equilibrium, it means no more solute can dissolve, and the solution is saturated.
4. Conclude based on the evidence: The lack of change in the crystal's size confirms that the solution is saturated.
5. Summarize: The solution is saturated because it has reached its maximum solubility, and the added crystal does not dissolve or grow.

Key Concepts

Saturated Solution

A saturated solution is one in which the maximum amount of solute has been dissolved in a solvent at a given temperature and pressure. In this state, any additional solute added will not dissolve and may remain as a solid, indicating that the solution has reached its limit of solubility.

Unsaturated Solution

An unsaturated solution is one that contains less solute than it has the capacity to dissolve at a given temperature and pressure. In this case, if more solute is added, it will continue to dissolve until the solution becomes saturated.

Equilibrium in Solutions

Equilibrium in solutions refers to the state where the rate of dissolution of solute equals the rate of crystallization. In a saturated solution, this equilibrium is established, meaning that the amount of solute remains constant over time, as seen when a crystal added to the solution does not change in size.