Kinetics and Collision Theory

Comprehensive vocabulary flashcards covering the concepts of chemical kinetics, collision theory, energy distribution graphs, and catalytic mechanisms as presented in the lecture notes.

Kinetics

The study of the factors that affect rates of chemical reactions and how quickly they take place.

Collision theory

A theory stating that for a reaction to take place, two particles must collide with enough energy to break bonds and at the correct orientation.

Activation energy ($E_a$)

The certain minimum energy required for a collision to result in a reaction and start breaking bonds.

Transition state (Activated complex)

The unstable, high-energy species that exists at the top of the curve on an enthalpy diagram, where bonds are in the process of being made and broken.

Exothermic reaction

A reaction where the products have less energy than the reactants, often showing a release of energy.

Endothermic reaction

A reaction in which the products have more energy than the reactants.

Species

A term used by chemists to refer to an atom, molecule, or ion.

Maxwell-Boltzmann distribution

A graph plotting the fraction of particles against their energy ($E$), illustrating that particles in a gas or solution move at various speeds and energies.

Most probable energy

The energy value corresponding to the peak of the Maxwell-Boltzmann distribution curve.

Catalyst

A substance that changes the rate of a chemical reaction by providing a different pathway with a lower activation energy, without being chemically changed itself.

Adsorption

The process where gas molecules form weak bonds with the metal atoms on the surface of a solid catalyst.

Desorption

The process where reaction products break away from the metal atoms of a catalyst surface, freeing up space for further reactions.

Zeolites

Minerals with a very open pore structure that can confine molecules in small spaces, changing their structure and reactivity.

Haber process catalyst

Iron, used in the reaction $N_2(g) + 3H_2(g) \rightarrow 2NH_3(g)$ to make fertilizers.

Ostwald process catalyst

Platinum and rhodium, used for making nitric acid for fertilizers and explosives.

Hardening of fats catalyst

Nickel, used to add hydrogen across double bonds to make margarines more solid.

Hydration of ethene catalyst

Phosphoric acid ($H_3PO_4$), used to produce ethanol.

Chlorofluorocarbons (CFCs)

Relatively unreactive compounds that decompose to produce chlorine atoms, which act as catalysts in the destruction of the ozone layer ($O_3$).

Montreal Protocol

The 1987 international agreement that resulted in the phasing out of CFCs to protect the atmosphere.