Lesson 7 - Reaction Rates and Chemical Equilibrium

Chemical Kinetics

the study of reaction rates

Rate of Reaction

the change in concentration of a reactant or product per unit time

Not Constant

The rate of reaction is _________ over a long period of time.

Initial Rate

the instantaneous rate determined just after the reaction begins; it is constant.

Rate at Later Time

Rate at which reactant is used up and the rate of reaction decreases

Effective Collision

A collision between two molecules or ions that results in a chemical reaction

Activation Energy

Minimum energy necessary to cause a chemical reaction

Inversely

The activation energy is ________ proportional to rate of reaction.

Transition State

a high-energy intermediate state of the reactants during a chemical reaction that must be achieved for the reaction to proceed

Directly

The concentration of the reactant is _______ proportional to the rate of reaction.

Rate Constant (k)

A proportionality constant between the molar concentration of reactants and rate of reaction.

Directly

Temperature is _______ proportional to the rate of reaction.

Catalyst

substance that speeds up the rate of a chemical reaction

Heterogenous Catalyst

Catalysts in separate phases from the reactants

Homogenous Catalyst

Catalysts in the same phase as the reactants

Reversible Reaction

a chemical reaction in which the products re-form the original reactants

Irreversible Reaction

a chemical reaction where products cannot revert back to reactants

Dynamic Equilibrium

A state in which the rate of the forward reaction equals to rate of reverse reaction

Chemical Equilibria

Equilibria established as a result of chemical reactions

Equilibrium Constant

the ratio of product concentrations to reactant concentrations at equilibrium, with each concentration raised to a power equal to the number of moles of that substance in the balanced chemical equation

Le Chatelier's Principle

States that when a stress is applied to a system in chemical equilibrium, the position of the equilibrium shifts in the direction that will relieve the applied stress

Henri Le Chatelier

put forth the statement known as Le Chatelier's principle

Reactants

An increase in temperature drives an exothermic reaction towards the ______

Products

An decrease in temperature drives an exothermic reaction towards the ______

Products

An increase in temperature drives an endothermic reaction towards the ______

Reactants

An decrease in temperature drives an endothermic reaction towards the ______

No Effect

Addition of catalysts to the reactions has _________ to the equilibrium constant/