Chemical kinetics explains how quickly chemical reactions occur and how their rates respond to changes in conditions. It also helps reveal reaction mechanisms and provides mathematical models for predicting chemical behavior.
Chemical kinetics is the branch of physical chemistry that studies reaction rates. Chemical thermodynamics concerns whether a reaction is energetically favorable and the extent to which it proceeds; by itself, thermodynamics does not say how fast the reaction occurs.
All flashcards
What is a rate law?
A mathematical relationship describing how reaction rate depends on concentrations of chemical species.
What is a reaction mechanism?
A sequence of elementary steps describing how reactants are converted into products.
What is activation energy?
The energy barrier that reacting molecules must overcome for a reaction to proceed.
How do kinetics and thermodynamics differ?
Kinetics concerns reaction speed; thermodynamics concerns favorability and equilibrium.
What is a kinetic isotope effect?
A change in reaction rate caused by replacing an atom with one of its isotopes.
Quiz questions
For a reactant being consumed, how is its rate of disappearance commonly expressed?Answer: As the negative time derivative of its concentration.
According to the Arrhenius relationship, what usually happens to a reaction's rate constant as temperature increases?Answer: It increases because a larger fraction of molecules can overcome the activation barrier.
What is the usual effect of a catalyst on the equilibrium position of a reversible reaction?Answer: It does not change the equilibrium position, though it speeds both directions.
How does a stopped-flow method make very fast reactions easier to study?Answer: It rapidly mixes reactant streams and begins observation after flow stops.
What is a common advantage of Runge–Kutta methods over the Euler method in numerical integration?Answer: They use additional slope evaluations and are often more accurate for a given step size.
Based on the Wikipedia article Chemical kinetics, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.