UNIT 5: Factors Affecting Reaction Rates and Reaction Mechanisms

These flashcards cover key vocabulary and concepts related to factors affecting reaction rates, collision theory, and reaction mechanisms.

Concentration

A measure of how much solute is in a given amount of solvent or solution.

Surface Area

The amount of substance exposed; smaller particle size increases surface area, leading to more collisions.

Temperature

A measure of the average kinetic energy of the particles in a sample; higher temperatures increase reaction rates.

Catalyst

A substance that increases the rate of a chemical reaction by lowering activation energy but is not consumed in the reaction.

Activation Energy

The minimum amount of energy that two particles need to collide to form products.

Collision Theory

Atoms, ions, and molecules must collide in a specific manner for a reaction to occur.

Rate Law

An equation that links the reaction rate with the concentration of reactants.

First Order Reaction

When the concentration of a reactant doubles, the rate of reaction doubles.

Second Order Reaction

When the concentration of a reactant doubles, the rate of reaction quadruples.

Third Order Reaction

When the concentration of a reactant doubles, the rate of reaction increases by eight times.

Intermediate

A substance that is produced in one step of a reaction mechanism and consumed in a subsequent step.

Overall Reaction

The reaction obtained by adding each step of a mechanism, excluding substances present on both sides.

Potential Energy Diagram

A graph that shows the energy changes during a chemical reaction, with peaks representing transition states.

Order of Reactants

Indicates how the concentration of each reactant affects the rate of the reaction.

k (rate constant)

A constant used in the rate law that is determined from experimental data and has specific units.

Rate Determining Step

The slowest step in a reaction mechanism that determines the overall reaction rate.