AP Chem Unit 5 Kinetics

Kinetics

The area of chemistry concerned with reaction rates.

Reaction Rate

A measure of the change in concentration of reactants or products over time.

Spectroscopy

A method to study kinetics using a spectrometer to measure light absorption.

Catalyst

A substance that speeds up a reaction without being consumed.

Collision Theory

A theory stating that for a reaction to occur, reactants must collide with sufficient energy and the correct orientation.

Activation Energy (Ea)

The minimum energy required for a reaction to occur.

Endothermic Reaction

A reaction that absorbs energy (positive ΔH).

Exothermic Reaction

A reaction that releases energy (negative ΔH).

Rate Law

An equation that relates the reaction rate to the concentration of reactants.

Differential Rate Law

Relates the reaction rate to the concentration of reactants.

Integrated Rate Law

Relates the concentration of reactants to time.

Zero-Order Reaction

A reaction where the rate is independent of the concentration of the reactants.

First-Order Reaction

A reaction where the rate is directly proportional to the concentration of one reactant.

Second-Order Reaction

A reaction where the rate is proportional to the square of the concentration of a reactant.

Rate Determining Step (RDS)

The slowest step in a reaction mechanism that determines the rate of the overall reaction.

Arrhenius Equation

Describes how the rate constant (k) depends on temperature and activation energy.

Half-Life (t1/2)

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

Enzyme

A biological catalyst that speeds up chemical reactions in living organisms.

Homogeneous Catalyst

A catalyst that is in the same phase as the reactants.

Heterogeneous Catalyst

A catalyst that is in a different phase than the reactants.

Intermediates

Substances that form during a reaction but are not present in the overall reaction equation.