Le Châtelier Placemat!
Predict the shift in equilibrium when more HI
q
(g)
is added to the system
H2 (g) + I2 (g) ↔ 2 HI (g)
Shift Left
No Change
Shift Right
Adding something on the product side of the reaction will cause equilibrium to shift to the reactant side. ‐the
the reverse reaction will be favoured
reverse reaction will be favoured
‐equilibrium shifts to the left
If more HI(g) is added to the system, how will the y
,
concentration of I2 change?
H2 (g) + I2 (g) ↔ 2 HI (g)
Decrease
No Change
Increase
For the reaction below, predict the direction the ,p
equilibrium will shift given the following changes. Temperature and volume are held constant.
2 NO2 (g) + 7 H2 (g) ↔ 2 NH3 (g) + 4 H2O(g)
Æ addition of ammonia
Shift Left
No Change
Shift Right
The concentration of I2 will increase
reverse reaction is favoured to use up the additional ammonia
For the reaction below, predict the direction the ,p
equilibrium will shift given the following changes. Temperature and volume are held constant.
2 NO2 (g) + 7 H2 (g) ↔ 2 NH3 (g) + 4 H2O(g)
Æ removal of water vapour
Shift Left
No Change
Shift Right
forward reaction is favored to replace the lost water vapour
For the reaction below, predict the direction the ,p
equilibrium will favour if the pressure is increased
2 SO2 (g) + O2 (g) ÅÆ 2 SO3 (g)
At a particular temperature, the following reaction has an equilibrium constant, Keq of 0.18
PCl3 (g) + Cl2 (g) ↔ PCl5 (g)
If More PCl3 3 is added to the system. Will the value of Keq increase or decrease?
Decrease
No Change
Increase
Changing the concentration of a reaction participant will not change the value of Keq. K
change the value of K
Keq will still equal 0.18 after equilibrium will still equal 0 18 after equilibrium
becomes re‐established.
For the reaction below, predict the direction the ,p
equilibrium will favour if the pressure is increased
AgCl(s) ÅÆAg1+(aq) + Cl
+ Cl11‐(aq)
Forward
No Change
Backward
‐ forward reaction is favoured
‐ there are fewer moles of gas on the product side.
there are fewer moles of gas on the product side
Forward
No Change
No change ‐ no gases are present
Backward
Would you increase or decrease the y
temperature to force the reaction in the forward direction?
H2 (g) + CO
+ CO2 (g) ÅÆ H2O(g) + CO
+ CO(g) ΔH
ΔH° = +41.0 kJ = +41 0 kJ
Will the value for Keq increase or decrease if the temperature is raised?
2 SO2 (g) + O2 (g) ÅÆ 2 SO3 (g) ΔH° = ‐198 kJ Decrease
Decrease
No Change
Explain the effect on K
p
y
g p
eq by using a platinum catalyst in the equilibrium reaction of yg
ammonia with oxygen:
4 NH3 (g) + 5 O
4 NH
+ 5 O2 (g) ÅÆ 4 NO
4 NO(g) + 6 H
+ 6 H2O(g) + heat
+ heat
No Change
Increase
Increase
Increase temperature, because the forward direction is endothermic and will use up the additional heat
endothermic and will use up the additional heat
Decrease
No Change
Increase
The addition of a catalyst will cause the system to reach equilibrium sooner but it will have no effect on Keq
equilibrium sooner, but it will have no effect on K
Keq will decrease. Increasing the temperature will favor the reactants.
reactants