Lesson 2: Factors Affecting Rate of Reaction

Vocabulary flashcards covering key terms from Lesson 2 on factors affecting rate of reaction.

Rate of reaction

The speed at which reactants are converted into products; influenced by concentration, temperature, surface area, catalysts, and collision frequency.

Collision Theory

A theory that chemical reactions occur when reactant particles collide with proper orientation and sufficient kinetic energy to break bonds and form products.

Activation Energy (Ea)

The minimum energy that reactant molecules must possess for a collision to be successful.

Kinetic Energy

Energy of motion; higher kinetic energy increases the likelihood of successful collisions.

Surface Area

The total area over which reactants can collide; larger surface area increases collision opportunities and reaction rate.

Concentration

The amount of reactant per unit volume; higher concentration increases collision frequency and reaction rate.

Temperature

A measure of thermal energy; higher temperature increases collision energy and frequency, boosting reaction rate.

Catalyst

A substance that increases the rate of a chemical reaction without being consumed; lowers activation energy.

Heterogeneous Catalyst

A catalyst that is in a different phase than the reactants (e.g., solid catalyst with gaseous or liquid reactants).

Homogeneous Catalyst

A catalyst that is in the same phase as the reactants (e.g., both aqueous).

Biological Catalyst

A catalyst produced by living systems; usually enzymes.

Enzymes

Biological catalysts that speed up biochemical reactions in living organisms.

Activation Complex (Transition State)

An unstable arrangement of atoms at the top of the reaction’s energy barrier, representing the maximum potential energy along the pathway.

Fraction Effective

The portion of collisions that lead to a successful reaction (are productive).

Collision Frequency

The number of collisions between reactant particles per unit time.

Rate of Reaction (conceptual formula)

Rate = collision frequency × fraction of collisions that are effective.

Exothermic Reaction

A reaction that releases heat to the surroundings.

Endothermic Reaction

A reaction that absorbs heat from the surroundings.