Glossary

First-Order (n = 1)

Criticality: 3

A reaction order where the rate of reaction is directly proportional to the concentration of a single reactant.

Example:

Radioactive decay is a classic first-order process, where the rate of decay is directly proportional to the amount of radioactive isotope present.

Half-life (t₁/₂)

Criticality: 3

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

Example:

If a medication has a half-life of 4 hours, then after 4 hours, half of the initial dose will have been eliminated from the body.

Integrated Rate Laws

Criticality: 3

Equations derived from differential rate laws that relate the concentration of a reactant to time. They are used to predict reactant concentrations at different points in time.

Example:

Using the integrated rate law for a first-order reaction, you can calculate how much reactant remains after a specific duration.

Rate Law

Criticality: 3

An experimentally determined equation that expresses the relationship between the rate of a reaction and the concentrations of the reactants.

Example:

For the decomposition of N₂O₅, the rate law is Rate = k[N₂O₅], indicating a first-order dependence on N₂O₅ concentration.

Rate constant (k)

Criticality: 3

The proportionality constant in the rate law that relates the reaction rate to the concentrations of reactants. Its value is temperature-dependent.

Example:

A large rate constant (k) for a reaction means it proceeds very quickly, like the combustion of hydrogen and oxygen.

Reaction Order (n)

Criticality: 3

The reaction order, denoted by *n*, describes how the concentration of a reactant affects the reaction rate. For AP Chemistry, it is typically an integer (0, 1, or 2).

Example:

If doubling the concentration of reactant A quadruples the reaction rate, the reaction order with respect to A is 2.

Second-Order (n = 2)

Criticality: 2

A reaction order where the rate of reaction is proportional to the square of one reactant's concentration or the product of two reactants' concentrations.

Example:

If a reaction is second-order with respect to reactant X, doubling [X] would quadruple the reaction rate.

Zeroth-Order (n = 0)

Criticality: 2

A reaction order where the rate of reaction is independent of the reactant's concentration, meaning the rate remains constant over time.

Example:

In a zeroth-order reaction, like some enzyme-catalyzed reactions at high substrate concentrations, the rate of product formation remains constant regardless of how much substrate is present.

Glossary

First-Order (n = 1)

Criticality: 3

A reaction order where the rate of reaction is directly proportional to the concentration of a single reactant.

Example:

Radioactive decay is a classic first-order process, where the rate of decay is directly proportional to the amount of radioactive isotope present.

Half-life (t₁/₂)

Criticality: 3

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

Example:

If a medication has a half-life of 4 hours, then after 4 hours, half of the initial dose will have been eliminated from the body.

Integrated Rate Laws

Criticality: 3

Equations derived from differential rate laws that relate the concentration of a reactant to time. They are used to predict reactant concentrations at different points in time.

Example:

Using the integrated rate law for a first-order reaction, you can calculate how much reactant remains after a specific duration.

Rate Law

Criticality: 3

An experimentally determined equation that expresses the relationship between the rate of a reaction and the concentrations of the reactants.

Example:

For the decomposition of N₂O₅, the rate law is Rate = k[N₂O₅], indicating a first-order dependence on N₂O₅ concentration.

Rate constant (k)

Criticality: 3

The proportionality constant in the rate law that relates the reaction rate to the concentrations of reactants. Its value is temperature-dependent.

Example:

A large rate constant (k) for a reaction means it proceeds very quickly, like the combustion of hydrogen and oxygen.

Reaction Order (n)

Criticality: 3

The reaction order, denoted by *n*, describes how the concentration of a reactant affects the reaction rate. For AP Chemistry, it is typically an integer (0, 1, or 2).

Example:

If doubling the concentration of reactant A quadruples the reaction rate, the reaction order with respect to A is 2.

Second-Order (n = 2)

Criticality: 2

A reaction order where the rate of reaction is proportional to the square of one reactant's concentration or the product of two reactants' concentrations.

Example:

If a reaction is second-order with respect to reactant X, doubling [X] would quadruple the reaction rate.

Zeroth-Order (n = 0)

Criticality: 2

A reaction order where the rate of reaction is independent of the reactant's concentration, meaning the rate remains constant over time.

Example:

In a zeroth-order reaction, like some enzyme-catalyzed reactions at high substrate concentrations, the rate of product formation remains constant regardless of how much substrate is present.