3.4 how conditioned affect chemical reactions

How can reaction rates be changed?

By conditions of a reaction

Types of changing factors

Pressure

Concentrations of reactants and products

Temperature

Presence of catalyst

Catalyst

substance that speeds up the rate of a chemical reaction

endothermic reaction

A reaction in which energy is absorbed (heat is absorbed)

Exothermic

Chemical Reaction in which energy is primarily given off in the form of heat (heat is released)

What does increase of pressure do to molecules and atoms

Increases the chance of collision between atoms and molecules

-increases reaction rate

What does increasing the reaction rate do?

Increases probability the reactants will come in contact with each other, thus increasing the likelihood of breaking or creating bonds

Equilibrium

The stage of chemical reactions in which both reactants and products are present and their concentrations no longer change

When a chemical reaction at equilibrium is perturbed, what happens

It responds by going in a direction in order to restore the equilibrium

Le Chatelier's Principle

a principle stating that when a chemical reaction at equilibrium is perturbed, it responds by proceeding in a direction that will restore the equilibrium

What does adding products do

Perturbs the equilibrium and then equation reestablishes by forming more reactions making it move to the LEFT (in problem 1, this causes a decrease in temperature of an exothermic reaction drives it to the right)

Adding products

shift left

What does adding reactants do

Drives the reaction to the right

What does removing products do

Moves the reaction to the right

Adding reactant

shifts right

removing reactant

shifts left

Activation energy

minimum energy needed to initiate the reaction