Le Chateliers Principal

Le Chatelier’s Principal def

when a chemicalsystem is at equilibrium is disturbed:

 the system will shift in a direction that minimizes the distrurbance,

given

N2O4 (g) – 2 NO2 (g)

if more NO2 is added what direction will the rxn go?

           

more product =

rxn will shift to the left

 

(aka it will convert the ‘extra’ product to reactants)

given

N2O4 (g) – 2 NO2 (g)

if more N2O4 is added what direction will the rxn go?

           

the rxn will shift to the right

 

(it will use the extra reactant to make more product)

CaCO3 (s)- CaO (s) + CO2 (g)

What is the effect of adding CaCO3?

nothing , Le Chatelier’s Principle only applies to  gases

 

solids, liquids, inert gases (do not affect the direction of the conc of the rxn)

In general if the pressure is increased then the volume is
decreased

The effect of volume / pressure changes on Equilibrium:

N2 (g) + 3 H2 (g)- 2NH3

If the pressure is HIGH what direction will the rxn go?

N2 (g) + 3 H2 (g)- 2NH3

4 moles  2 moles

 

This rxn will go from high to low

FORWARD


(high pressure causes it to flow from an area of high vol to an area of low volume)

The effect of volume / pressure changes on Equilibrium:

N2 (g) + 3 H2 (g)- 2NH3

If the pressure is LOW what direction will the rxn go?

rxn will flow from low to high concentration

 

(aka low pressure= high vol)

the effect of temperature change:

in an exothermic rxn

what if the temp is increased?

k will be?

rxn will shift

(reversible rxn)

k is decreased

 

 

*adding heat to a rxn that is already supposed to release heat causes it go back to reactants.

the effect of temperature change:

in an exothermic rxn

what if the temp is decreased?

k will be?

forward rxn

k increases

the effect of temperature change:

in an endothermic rxn

what if the temp is decreased?

k will be?

reverse rxn

k decreases

 

* remember endothermic rxns NEED heat

x

Hi!
I'm Larry

Hi there, would you like to get such a paper? How about receiving a customized one?

Check it out