Chemistry Study Guide: Clausius-Clapeyron, Acids/Bases, Equilibrium, Solutions & Kinetics

Clausius-Clapeyron Equation

Relates vapor pressure and temperature at two different conditions of the same substance with the formula $\ln\left(\frac{P_2}{P_1}\right) = -\frac{\Delta H_{vap}}{R}\left(\frac{1}{T_2}-\frac{1}{T_1}\right)$.

ΔHvap

The enthalpy change associated with the vaporization of a substance, always positive due to endothermic nature.

pH scale

A logarithmic scale from 0 to 14 indicating acidity or basicity; pH < 7 is acidic, pH = 7 is neutral, and pH > 7 is basic.

Arrhenius Acid

A substance that produces H⁺ ions in aqueous solution.

Arrhenius Base

A substance that produces OH⁻ ions in aqueous solution.

Ka

The acid dissociation constant, representing the strength of an acid in solution.

Kw

The ion product constant of water; $K_w = [H_3O^+][OH^-] = 1.0 \times 10^{-14}$ at 25°C.

Le Chatelier's Principle

When a system at equilibrium is disturbed, it shifts in a direction that counteracts the disturbance.

Vapor Pressure Lowering

The reduction in vapor pressure of a solvent when a solute is added, described by Raoult's Law: $P_{solution} = X_{solvent} \cdot P^\circ_{solvent}$.

Osmotic Pressure

The pressure required to stop the flow of solvent through a semipermeable membrane, calculated by $\pi = MRT$ for non-ionic solutions.

Integrated Rate Law

Mathematical expressions that relate the concentration of reactants to time for different order reactions.

Half-life (t₁/₂)

The time required for the concentration of a reactant to decrease to half its initial value.

First-Order Reaction

A reaction whose rate is directly proportional to the concentration of one reactant; integrated form is $\ln[A]_0/[A] = kt$.

Second-Order Reaction

A reaction whose rate depends on the concentration of one reactant squared or the concentrations of two reactants; integrated form is $\frac{1}{[A]} - \frac{1}{[A]_0} = kt$.

Rate Constant (k) Units

Units of the rate constant vary based on reaction order; for first-order reactions, units are s⁻¹.

Colligative Properties

Properties that depend on the number of solute particles in a solution, not their identity.

Molarity (M)

A measure of concentration defined as moles of solute per liter of solution.

Molality (m)

A measure of concentration defined as moles of solute per kilogram of solvent.

Conjugate Acid-Base Pair

Two species that differ by the presence or absence of a proton (H⁺).