Kinetics Summary Flashcards

Flashcards covering key concepts in chemical kinetics, including factors affecting reaction rates, rate laws, and catalysts.

Collision Theory

Collision theory states molecules must have the right orientation, activation energy, and frequency to react.

Reaction Rate Factors

Factors affecting reaction rates include reactant concentration, temperature, reactant surface area, pressure, and catalysts.

Rate Law

Rate = k[A]^n[B]^m, where n + m = overall reaction order. Determined by the rate-determining step.

Instantaneous Rate

Rate at a single point in the reaction.

Initial Rate

Instantaneous rate at the start of the reaction.

Average Rate

Rate across multiple points.

Activation Energy

Minimum energy of molecular collisions required to break bonds in reactants to form products.

Catalysts

Lower activation energy by providing an alternate mechanism.

Homogeneous Catalyst

Physical states are the same as the reactants.

Heterogeneous Catalyst

Physical states are different than the reactants.

Elementary Steps

Single steps that take place to complete the overall reaction.

Intermediates

Species that appear in the reaction mechanism but not in the overall balanced equation.

Activated Complex/Transition State

Point of highest energy along the reaction pathway.

Rate Determining Step

The step with the largest activation energy or slowest step.

Reaction Rate

How rapidly a reaction occurs; Rate = Δconcentration/Δtime

Units for k

M^(1-n)s^(-1)

Intermediate in the reaction H2O2 + I- → IO-+ H2O and H2O2 + IO- → I- + H2O + O2

IO-

Catalyst in the reaction H2O2 + I- → IO-+ H2O and H2O2 + IO- → I- + H2O + O2

I-