Kinetics Terms
Reaction Kinetics
Measuring how fast a reaction occurs. Someone has to do it, right?Chemical Kinetics
Just like reaction kinetics.Kinetics
Just like reaction kinetics, too. Favored by lazy people who don't want to write an extra work.Equilibrium
Describes a system that is stable, i.e. no longer changing.Collision Theory
For reactions to happen, atoms or molecules need to smack each other hard enough and in the right geometry. "Bumper car" theory wouldn't be a bad name either.Activation Energy
Energy needed to make things happen. For couch potatoes, the energy required to get up and go to the bathroom. For reactions, the energy needed to make the reaction happen.Transition State Theory
Reactions go through a path where they become less like reactants and more like products. Like adolescence for molecules.Activated Complex
A state in-between reactants and products. A sort of ½ reactant, ½ product, Frankenstein-like creation. It does not last long.Catalyst
Substance that lowers the activation energy, making a reaction happen faster.Reaction Rate
How fast a reaction happens under given conditions.Rate Law
Mathematical expression that describes the kinetics of a given reaction. You can't fight the rate law, it will win.Rate Constant
That pesky k in the rate law equation.Reaction Order
Those crazy exponents above the concentrations in a rate law.- Zeroth (0th) Order–Exponent = 0
- First (1st) Order – Exponent = 1
- Second (2nd) Order – Exponent = 2
Overall Rate Law
Sum of reaction orders of all reactants.Half-Life
Time needed for the concentration of reactants to go down by ½.Arrhenius Equation
Equation that relates the rate constant k to activation energy.Frequency Factor (A)
Constant in Arrhenius equation, which describes how often molecules collide the "proper" way for a reaction to occur. Proper collisions sound very British, but frequency factors can be found anywhere.Dynamic Equilibrium
Equilibrium where individuals may be changing, but the system as a whole is not changing.Equilibrium Constant
Constant defined for a reaction at given conditions. [product]coeff-prod./[reactants]coeff-react.LeChatelier's Principle
A disturbance to an equilibrium system is resisted by the system.Thermodynamics
The study of heat and energy in chemistryFirst Law Of Thermodynamics
Heat + work = change in internal energy. Or q + w = ΔU.Second Law Of Thermodynamics
The total entropy of the universe (system and surroundings) increases for spontaneous processes.Third Law Of Thermodynamics
Perfect crystal + absolute zero Kelvin = zero entropyInternal Energy
Sum of all kinetic and potential energy in a chemical system. Includes bonds and thermal motion.Heat
Thermal energy transfer from hot to cold. Or Miami's basketball team. Whatever.Work
Force times distance.Enthalpy
Heat given off or absorbed in a chemical reaction.Entropy
A measure of disorder.Free Energy
Thermodynamics version of a thumbs up or thumbs down for whether a reaction occurs naturally.- Reactions with a –ΔG value = Thumbs up.
- Reactions with a +ΔG value = Thumbs down.