Chemical Equilibrium

How are products formed?

Molecules that collide with other and break bonds force the reactants to rearrange and form products. others

Collision model

Collisions forming products

Why will a reaction speed up in terms of concentration?

higher concentrations means more molecules per unit volume which leads to more reaction events

Why does reaction rate speed up at higher temperatures?

quicker moving molecules from heat (kinetic energy), which causes more opportunities for the molecules to break down.

Activation energy

the minimum amount of energy required to start a chemical reaction

Catalyst

substance that speeds up the rate of a chemical reaction without being consumed

Example of Catalyst

enzymes in our body

What do the enzymes do?

allow our bodies to speed up complicated reactions that would be too slow to sustain life at normal body temperatures

How does a catalyst work

(lowers EA) It provides a new pathway for the reaction, which has a lower activation energy than the original pathway.

What are the ways to make a reaction form products quicker?

1. Higher concentration

2. Higher temperature

3. Adding a Catalyst

What is chemical equilibrium?

Chemical equilibrium occurs when the forward and reverse reactions are proceeding at the same rate.

What happens to the concentrations of reactants and products at chemical equilibrium?

The concentrations of all reactants and products remain constant.

What conditions are required for chemical equilibrium to occur?

Chemical equilibrium occurs under the same conditions.

How many reactions are going on at equillibrium equilibrium?

2 reactions are going on, but you can write it as one.

What type of situation is equilibrium?

a dynamic situation

what is a dynamic situation?

when two opposing processes are taking place at the same time and at the same rate.

What are the rates of the forward and reverse reaction at equillibrium?

the rates are equal to eachother

Le Chateliers Principle

In any equilibrium when a change is made to some external factor such as temperature, volume, pressure, or concentration, then the position of the equilibrium shifts in a direction that tends to reduce the effect of that change.

What is the relationship between pressure and volume?

They're inversely related

Endothermic (+)

Reactant side

Exothermic (-)

Product side

Which temperature reaction do chemists favor?

An increase in temperature favors the endothermic reaction because it shifts the equilibrium to the right (forward).

What has an affect of KEQ

temperature

Does a catalyst favor a reaction?

No, it makes the reaction quicker by increasing the rates of both forward and reverse reactions equally but doesn't cause an equilibrium shift.

Is KEQ temperature-dependent?

Yes!

What is KEQ

the equilibrium constant

What are the square brackets?

the concentration of the substance at equilibrium

Equilibrium expression meaning

for a given reaction at a given temperature, the special ratio of the concentrations of the products to reactants defined by the equilibrium expression will always be equal to the same number.

Keq > 1

products are favored

Keq = 1

equilibrium

Keq < 1 means

reactants are favored

Hetergenous equillibrium

results from a reversible reaction involving reactants and products that are in different phases

What states aren't included in equilibrium expression expression?

Solids and liquids

Why are solids and liquids not included?

they are an intensive property, and their concentration cannot change

intensive property

a property that depends on the type of matter in a sample, not the amount of matter

What is another example of an intensive property?

Density,

What is KSP

solubility of a solid

In terms of solubility for KSP, the smaller the number means

its less soluble.

Saturated

no more solid dissolves.

Is a solution saturated at equilibrium?

yes

what is going on if a solution saturated at equilibrium

the solid is dissolving at the same rate at which dissolved ions are reforming the solid.

ion product constant

KSP

solubility product constant

ksp

has an unsaturated solution reached equilibrium?

no

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equilibrium molarity