Equilibrium

Equilibrium

By Angela West

Multiple Select

The two things that molecules need in order to react with each other are:

• Be in the right orientation

• Be facing each other

• Be moving really fast

• Having enough energy

Multiple Choice

What is equilibrium?

• Something that can't change

• Something that's always changing

• Balance within a system

​Most chemical reactions can go forward or reverse (like your car)

Chemistry | Equilibrium

Hopefully equilibrium doesn't "stress" you out

Draw

NaCl + KI ->

Draw

$$NaI\ +\ KCl->$$  

​The second reaction was the "reverse" of the first one.

NaCl + KI -> NaI + KCl​

NaI + KCl -> NaCl + KI

​

NaCl + KCl <==> NaI + KCl​

​

Forward and reverse arrows (<==>) means the reaction is reversible​

Chemistry | Equilibrium

Forward and reverse depend on what you designate as your reactants

Multiple Choice

When a reaction starts you have more ___ and less ____

• products, reactants

• reactants, products

Multiple Choice

When a reaction reaches equilibrium

• You have more products than reactants

• You have more reactants than products

• You have equal amounts of product and reactants

• The concentrations of the reactants and products don't change

​Equilibrium in the chemical industry is no bueno (usually)

Generally speaking you're trying to make products (to make money) so you have to find ways to "mess with" the reaction so that making products is favorable over having the products break back down into the reactants.

Chemistry | Equilibrium

​Because who doesn't want to make money after all?

"Messing with" a reaction is putting stress on the system in order to disrupt the equilibrium

When stress is put on a system at equilibrium, the system will shift to relieve the stress and try to re-establish equilibrium.​

Chemistry | Equilibrium

​Like when you shut yourself in your room because your parents are driving you nuts

Multiple Select

"Stresses" that can be put on reactions to disrupt the equilibrium are

• Changes in concentration of reactants and/or products

• Changes in temperature

• Changes in pressure and/or volume

• Changes in gravity

Which types of stress affect which types of reactions?

​First look at the phase(s) of the reaction

1. Pressure will have NO impact on an aqueous system (liquids can't be compressed).

2. Pressure WILL have an impact on gaseous systems (Remember all those gas laws?)​

​For some people, stress makes them more "gaseous"

Which types of stress affect which types of reactions?

​For all phases (aqueous, gaseous, or a combination of the two):

1. Changes in c​oncentrations of reactants and/or products will have an impact

2. Changes in temperature of the system will have an impact​

Changes in volume will result in changes of concentration

Anything that potentially speeds up or slows down a reaction at equilibrium will disrupt the equilibrium

​

Reactions require species to "run into each other" in a specific orientation at sufficient speed. Anything that can increase or reduce either of those will shift the equilibrium.​

Remember the two people where one of them got the arm of the other one stuck to his face?

​How do we know how much a reaction at equilibrium has been disrupted?

​You guessed it! MATH!

​Mr. Stanberry will be so proud!