Equilibrium: How is your balance?

Physical Science December 12, 2011

Ms Cillipages 216-219

Physical Science pages 216-219

Physical Science pages 216-219

Objectives

Identify and describe physical and chemical equilibria.

Describe the factors affecting chemical equilibrium.

Physical Science pages 216-219

Ever rode a seesaw?

Physical Science pages 216-219

Equilibrium

A state in which the forward and reverse paths of a change take place at the same rate

What are the two types of changes?

1. 2.

REVERSIBLE REACTION

Physical Science pages 216-219

When physical change does not go to completion, a physical equilibrium is established

The forward and reverse changes are the same

Example: slushie

Physical Science pages 216-219

Physical Equilibrium

Physical Science pages 216-219

Physical Science pages 216-219

Chemical Equilibrium

Occurs when the reaction does not go to completion

Example:

All together now…

A physical

equilibrium is

established

between the

forward and reverse

reactions when the

physical change

does not go to

completion

A chemical

equilibrium is

established

between the

forward and reverse

reactions when the

chemical change

does not go to

completionPhysical Science pages 216-219

Physical Science pages 216-219

When a change is introduced into a

system in equilibrium, the

equilibrium shifts in the direction that

relieves the change

Henri Le Châtelier

1.

2.

3.

Physical Science pages 216-219

Factors that affect equilibrium:

If energy is added to one side, the other side will release it

Physical Science pages 216-219

Factors that affect equilibrium: Temperature

If the reaction is endothermic (adding heat), when the reaction is reversed the heat will be ________. (exothermic).

Physical Science pages 216-219

Factors that affect equilibrium: Temperature

What happens when you squeeze a balloon?

Physical Science pages 216-219

Factors that affect equilibrium: Pressure

If you increase the pressure on one side, it will shift direction to ________ the pressure

Physical Science pages 216-219

Factors that affect equilibrium: Pressure

What happens if you increase the amount of ingredients (reactants) when making a cake?

Physical Science pages 216-219

Factors that affect equilibrium:

Concentration

Physical Science pages 216-219

Factors that affect equilibrium:

Concentration

Physical Science pages 216-219

Closure True or false:

In chemical equilibrium, the rate of forward reaction does not equal the rate of the reverse reaction.

The three factors that affect chemical equilibrium are:

A. PressureB. TemperatureC. ConcentrationD. VolumeE. Only A, B, and C

Assignment: Independent Work:

Read section 7.5 in the book Start studying for the test Finish the study guide

Homework: Section 7.5 HW due Tuesday, December

13th by 8PM

Physical Science pages 216-219