Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Chemical Kinetics: Reaction Rates

Description

This lecture covers chemical kinetics, focusing on reaction rates, speed laws, and the influence of concentration and temperature on reaction rates. It explains the concepts of elementary reactions, reaction mechanisms, and activation energy. The lecture also discusses multi-step reactions, catalysis, and enzyme kinetics.

Instructor

Samuel Terrettaz

Official source

Ontological neighbourhood

Chemistry

Physical chemistry: Chemical kinetics

Related concepts (32)

Reaction mechanism

In chemistry, a reaction mechanism is the step by step sequence of elementary reactions by which overall chemical reaction occurs. A chemical mechanism is a theoretical conjecture that tries to describe in detail what takes place at each stage of an overall chemical reaction. The detailed steps of a reaction are not observable in most cases. The conjectured mechanism is chosen because it is thermodynamically feasible and has experimental support in isolated intermediates (see next section) or other quantitative and qualitative characteristics of the reaction.

Reaction rate

The reaction rate or rate of reaction is the speed at which a chemical reaction takes place, defined as proportional to the increase in the concentration of a product per unit time and to the decrease in the concentration of a reactant per unit time. Reaction rates can vary dramatically. For example, the oxidative rusting of iron under Earth's atmosphere is a slow reaction that can take many years, but the combustion of cellulose in a fire is a reaction that takes place in fractions of a second.

Chemical reaction

A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur.

Rate equation

In chemistry, the rate law or rate equation for a chemical reaction is a mathematical equation that links the rate of forward reaction with the concentrations or pressures of the reactants and constant parameters (normally rate coefficients and partial reaction orders). For many reactions, the initial rate is given by a power law such as where [\mathrm{A}] and [\mathrm{B}] express the concentration of the species \mathrm{A} and \mathrm{B}, usually in moles per liter (molarity, M).

Reaction intermediate

In chemistry, a reaction intermediate or an intermediate is a molecular entity that is formed from the reactants (or preceding intermediates) but is consumed in further reactions in stepwise chemical reactions that contain multiple elementary steps. Intermediates are the reaction product of one elementary step, but do not appear in the chemical equation for an overall chemical equation. For example, consider this hypothetical stepwise reaction: A + B -> C + D The reaction includes two elementary steps: A + B -> X X -> C + D In this example, X is a reaction intermediate.

Related lectures (34)

Chemical Reaction Mechanisms: Chain React

Explores reaction mechanisms, chain reactions, catalysis, enzyme catalysis, galvanic cells, and electromotive force in batteries.

Reaction Kinetics: Temperature Influence

Discusses temperature's impact on reaction rates, activation energy, collision efficiency, reaction mechanisms, catalysis, and enzymatic catalysis.

Chemical Kinetics: Elementary Reactions and Reaction Rates

Explores chemical kinetics, reaction rates, reaction orders, rate constants, and enzymatic catalysis.