Equilibrium Vocabulary

Chemical Equilibrium

Forward and reverse reaction rates are equal

Dynamic Equilibrium

Both reactions continue, but concentrations stay constant

Reversible Reaction

Reactants form products, and products form reactants

Collision Theory

Particles must collide with enough energy and correct orientation to react

Reaction Rate

How fast a chemical reaction occurs

Concentration

Amount of substance in a given volume

Catalyst

Speeds up a reaction by lowering activation energy; isn’t used up

Le Chatelier’s Principle

An Equilibrium system shifts to oppose an applied stress

Haber Process

Makes ammonia (NH_3) from nitrogen and hydrogen

Activation Energy

Minimum energy needed to start a chemical reaction

Closed System

A system where no substances enter or leave

Inhibitor

A substance that slows down a chemical reaction

Surface Area

Smaller particles expose more surface area, increasing collisions

Temperature and Reaction Rate

Higher temperature increases particle speed and collision frequency

Concentration and Reaction Rate

Higher concentration increases collision frequency

Exothermic Reaction

A reaction that releases heat; heat is a product

Endothermic Reaction

A reaction that absorbs heat; heat is a reactant

Enthalpy

The energy difference between reactants and products

Equilibrium Constant (K_eQ)

The ratio of product concentrations to reactant concentrations at equilibrium

Forward Reaction

Reactants turn into products; product concentrations increases

Reverse Reaction

Products turn into reactants; reactant concentration increases

Equilibrium Shift

A change in the balance of reactants and products after stress

Pressure and Equilibrium

Increasing pressure favors the side with fewer gas particles

Non-Reversible Reaction

A reaction that goes to completion and does not establish equilibrium

Precipitate

An insoluble solid formed during a chemical reaction