Chapter 11: Solutions and Colloids

Vocabulary flashcards covering the fundamental concepts of solutions, electrolytes, solubility trends, concentration units, and colligative properties.

Solution

A homogeneous mixture of two or more substances.

Solvent

The component of a solution present in the highest concentration.

Solute

The component of a solution present in a lower concentration.

Solute-Solvent Interaction Rule

The condition where the solute will dissolve if the attraction between the solute and solvent is greater than the attraction between solute particles.

Strong electrolyte

A substance that dissociates completely into ions when dissolved in water, such as ionic compounds, strong acids, and strong bases, allowing it to conduct electricity.

Weak electrolyte

A substance that only partially dissociates into ions in solution, meaning both ions and molecules are present, and it conducts electricity weakly.

Nonelectrolyte

A substance that does not dissociate into ions, staying as intact molecules in solution (e.g., covalent compounds like $C_{12}H_{22}O_{11}$), and does not conduct electricity.

Solubility

The maximum concentration of a solute that may be achieved under given conditions when the dissolution process is at dynamic equilibrium.

Saturated solution

A solution that contains the maximum amount of solute that can dissolve in a solvent at a specific temperature.

Unsaturated solution

A solution containing a concentration of solute that is below its solubility limit.

Supersaturated solution

A solution containing a concentration of solute that exceeds its normal solubility limit.

Temperature Effect on Gas Solubility

The solubility of a gas in water decreases as temperature increases because higher kinetic energy allows gas particles to overcome intermolecular forces and enter the gas phase.

Pressure Effect on Gas Solubility

Increasing pressure increases the solubility of a gas in a liquid due to more gas molecules colliding with the liquid surface.

Molarity ($M$)

A unit of concentration defined as $\text{Molarity}(M) = \frac{\text{amount solute (in mol)}}{\text{volume solution (in L)}}$.

Molality ($m$)

A unit of concentration defined as $\text{Molality}(m) = \frac{\text{amount solute (in mol)}}{\text{mass solvent (in kg)}}$.

Mole fraction of solute (\text{\chi}_{\text{solute}})

The ratio of the amount of solute in moles to the total amount of solute and solvent in moles: \text{\chi}_{\text{solute}} = \frac{n_{\text{solute}}}{n_{\text{solute}} + n_{\text{solvent}}}.

Colligative Properties

Properties that depend on the concentration of solute molecules or ions in solution, but not on the identity of the particles.

van 't Hoff factor ($i$)

The ratio of moles of particles in a solution to the moles of formula units dissolved: $i = \frac{\text{moles particles in solution}}{1\text{\,mole of formula units dissolved}}$. For nonelectrolytes, $i = 1$.

Raoult’s Law

A law used to determine the vapor pressure of a solution: P_{\text{solution}} = \text{\chi}_{\text{solvent}} P^{\circ}_{\text{solvent}}.

Boiling Point Elevation (\text{\Delta} T_b)

The increase in the boiling point of a solvent due to the addition of a solute, calculated as \text{\Delta} T_b = i \times m \times K_b, where $K_b$ is the boiling point elevation constant.

Freezing Point Depression (\text{\Delta} T_f)

The decrease in the freezing point of a solvent due to the addition of a solute, calculated as \text{\Delta} T_f = i \times m \times K_f, where $K_f$ is the freezing point depression constant.

Osmosis

The diffusion of solvent molecules through a semipermeable membrane from a solution of higher solvent concentration to one of lower solvent concentration.

Osmotic Pressure (\text{\Pi})

The pressure required to prevent the movement of solvent molecules through a semipermeable membrane, calculated as \text{\Pi} = i \times M R T.

Ideal Gas Constant ($R$)

The constant used in osmotic pressure equations, defined as $0.08206\text{\,atm} \times L/mol \times K$.