Transcript Le Chatalier’s Principle - Chandler Unified School District

LE CHATELIER’S PRINCIPLE
 Definition
 Changes in
concentration
 Way to predict changes that
occur when an equilibrium
system is disturbed
 N 2(g) +3H 2(g)  2NH 3(g)
 Rate of forward reaction
increases until equilibrium is
reestablished.
 Increase in N 2 or H 2
 K eq remains the same
 Equilibrium position shifts right
LE CHATELIER’S PRINCIPLE
 Changes in
Concentration
(continued)
 Increase in NH 3
N 2 +3H 2 2NH 3
 Rate of reverse reaction
increases until equilibrium is
reestablished
 K eq stays the same
 Equilibrium position shifts to
the left
 Decrease in reactants  Equilibrium position shifts to
the left
 Decrease in products
 Equilibrium position shifts to
the right
LE CHATELIER’S PRINICIPLE
Changes in Concentration
2H 2(g) + O 2(g)  2H 2 O (l)
 Increase in reactants
 Equilibrium position shifts
right
 Increase in products
 No shift in equilibrium
position
 H 2 O (l) not a dispersed phase
LE CHATELIER’S PRINCIPLE
Changes in Volume
N 2 +3H 2 2NH 3
 Decrease volume
of system
 Pressure increases
 Equilibrium position will shift to
side with fewest dispersed
molecules
 Above reaction shifts right
 K eq stays the same
 Increase in
volume
 Equilibrium position shifts to
side with most dispersed
molecules
 Above shifts left
LE CHATELIER’S PRINCIPLE
Changes in Temp
 Decrease
temperature of
system
 Increase in
temperature
N 2 +3H 2 2NH 3 + Energy
 Energy Decreases
 Equilibrium position will shift to
side with less stored chemical
energy
 Above reaction shifts right
 K eq changes!!
 Equilibrium position shifts to
side with most stored chemical
energy
 Above shifts left