kinetics and rate

why is activation energy important?

activation energy must be overcome for reactants to turn into products

activation energy is always positive

what is reaction rate proportional to the concentration of?

proportional to concentration of the transition state at any given moment

a higher E_A means it is harder to reach the TS, therefore there is a lower concentration of TS and the reaction is slower

what is the rate constant, k?

proportionality factor that quantifies the speed and direction of a chemical reaction

relates reaction rate to molar concentration

dependent on temperature

what is the reaction rate?

measured in M s^-1

change in concentration of reactants or products per unit time

what is the arrhenius equation?

A also referred to as Arrhenius factor

what does the arrhenius equation model?

models the dependence of a chemical reaction’s rate constant on temperature, activation energy and pre-exponential factor

what is the pre-exponential factor

the frequency of collisions with the correct orientation

what is the relationship between Ae, ΔG and rate constant?

inverse and exponential

a larger ΔG —> smaller k

what is the rate equation?

• [A] and [B]: The molar concentrations of the reactants.

• m and n: The reaction orders with respect to reactants A and B (e.g., 0 for no effect, 1 for directly proportional, or 2 for a squared relationship)

what does the rate equation show?

links the reaction rate to reactant concentrations

determined experiementally

units depend on order of reaction