Chemical Equilibrium: Keq
2H2S(g)  2H2(g) + S2(g)
At 1130oC the following equilibrium
concentrations are as follows:
H2S = 0.15 M; H2 = 0.01 M;
S2 = 0.051 M. Calculate Keq.
Chemical Equilibrium: Keq
H2(g) + I2(g)  2HI(g)
What is the equilibrium concentration
of HI for the above reaction given the
following information:
H2(g) equilibrium conc. = 2.0M;
I2(g) equilibrium conc. = 3.0M;
Keq=51
Chemical Equilibrium: Keq
At 900 K, a 4.00 L reaction vessel
originally contained 0.55 mols SO3(g).
Once equilibrium was reached, 0.12
mols of O2(g) was made. Calculate the
Keq given the following equation:
2SO3(g)  2SO2(g) + O2(g)
Chemical Equilibrium: Keq
A 1.00 M sample of HI is heated in a
sealed container to 510oC. At
equilibrium, a 0.14 M concentration of
each of the products (H2 & I2) is
present. Calculate the Keq.
Chemical Equilibrium: Keq
At 500 K, a 1.00 L reaction vessel
originally contained 0.045 mols
NO2(g). Once equilibrium was
reached, 0.0020 mols of O2(g) was
made. Calculate the Keq given the
following equation:
2NO2(g)  2NO(g) + O2(g)
Shifts: Le Chatelier
The following system is in equilibrium:
Heat + 2NH3(g) N2(g) + 3H2(g)
1. If more N2(g) were added, what effect on
the equilibrium would there be?
2. If H2(g) could be selectively removed
from the system, what effect would there be
on the equilibrium?
Le Chatelier
For the system 2 SO2(g) + O2(g) 2 SO3(g) ,
Predict the effect of each of the following
changes on the value of the equilibrium constant
and on the number of moles of SO3 present in the
mixture at equilibrium.
(a)
(b)
(c)
Decreasing the volume of the system.
Adding oxygen to the equilibrium mixture.
Raising the temperature of the system.
Le Chatelier
C(s) + H2O(g)  CO(g) + H2(g)
Ho = +131 kJ
1. Additional H2(g) is added.
2. The temperature of the system is
increased.
3. The volume of the container is
decreased.
4. The graphite pellets are pulverized
Solubility Product: Ksp
At 25oC, a saturated solution of
calcium hydroxide has a concentration
of 0.0126 M. Calculate the Ksp.
Solubility Product: Ksp
The solubility of calcium sulfate is
found to be 0.67 grams per liter of
solution. Calculate the Ksp.
Solubility Product: Ksp
The Ksp for silver carbonate is
8.1 x 10-12 at 25oC. Calculate the molar
solubility of this substance at this
temperature.
Solubility Product: Ksp
Solid calcium nitrate is added to a
100.0 ml solution of 0.10 M KF until
the reaction stops. How many grams of
solid CaF2 is produced and what is the
molar solubility of the of CaF2
(Ksp = 3.9 x 10-11)
Solubility Product: Ksp
At 25oC, the Ksp of silver carbonate,
Ag2CO3 is 8.1 x 10-12. Calculate the
molar concentrations of silver and
carbonate ions at this temperature.
Solubility Product: Ksp
a) At 25 degrees the Ksp of magnesium
carbonate (MgCO3) is 3.60 X 10-8. Calculate the
molar concentration of Magnesium ions present
in a saturated solution at this temperature.
b) If you were asked to prepare a solution of this
substance at this temp. by dissolving 0.240 grams
MgCO3 into 10.0 L, would all the solute
dissolve? If not, how much (in grams) would be
left undissolved?
Solubility Product: Ksp
If 0.01 L of a 0.00825 M solution
of Na2SO4 is added to 0.29 L of a
0.00125 M solution of CaCl2, will
a CaSO4 precipiate form, and if so
how much? The Ksp for
CaSO4 = 1.7 x 10-8