Unit 5: Solutions Study Guide

Definitions and Basic Concepts

• Solution: A homogeneous mixture composed of a solute dissolved in a solvent.

• Components:

  • Solute: The substance that is dissolved (e.g., salt in saltwater).

  • Solvent: The substance that dissolves the solute (e.g., water in saltwater).

Miscibility

• Miscible: Substances that can mix in any ratio without separating (e.g., alcohol and water).

• Immiscible: Substances that do not mix (e.g., oil and water).

Types of Solutions

• Aqueous Solution: A solution where water is the solvent.

• Saturated Solution: A solution in which no more solute can dissolve at a given temperature.

• Supersaturated Solution: A solution that contains more solute than what can normally dissolve at a specific temperature.

Electrolytes

• Electrolyte: A substance that dissolves in water to produce a solution that conducts electricity.

• Strong Electrolytes: Ionic compounds that dissociate completely in solution (e.g., NaCl).

• Non-Electrolytes: Substances that do not ionize in solution (e.g., sugar).

Factors Affecting Solubility

• Solubility of Solids in Water: Generally increases with increasing temperature.

  • Example: Sugar dissolves better in hot water than in cold.

• Solubility of Gases in Water: Generally increases with decreasing temperature and increasing pressure.

  • Example: More carbon dioxide can dissolve in water when the pressure is high (as in soda).

Concentration of Solutions

• Dilute Solution: Contains a small amount of solute relative to the solvent.

• Concentrated Solution: Contains a large amount of solute relative to the solvent.

Molarity (M)

• Molarity Formula: M = \frac{n}{V}

  • Where:

  • M = Molarity (mol/L)

  • n = Number of moles of solute

  • V = Volume of solution in liters

Units of Molarity Equation

• n: Moles (mol)

• V: Volume (L)