REACTION RATES AND GIBB’S FREE ENERGY
Name
1. Given the following data, calculate the rate law for the reaction and the value for k.
A + B  AB
[A]
[B]
Initial Rate (M/s)
1.0
1.0
1.2 x 10-2
1.0
2.0
4.8 x 10-2
1.0
4.0
1.9 x 10-1
2.0
1.0
2.3 x 10-2
4.0
1.0
4.9 x 10-2
8.0
1.0
9.6 x 10-2
(1.2 x 10-2 M-2/s)
2. State whether the values for
H and S would be positive or negative and favorable or
unfavorable. Use these estimates to predict whether G would be negative at all temperatures,
high temperatures, low temperatures or no temperatures.
a.
2 O3 (g)  3 O2 (g) + heat
b.
CaO (s) + CO2 (g)  CaCO3 (s) + heat
c.
2 NO (g) + O2 (g) + heat  2 NO2 (g)
d.
C2H2OH (l) + 3 O2 (g) + heat  2 CO2 (g) + 3 H2O (g)
e.
N2O5 (g) + H2O (l)  2 HNO3 (l) + heat
3. Using the values for standard entropy and standard enthalpy, determine whether the formation
of Carbon Dioxide gas and Ammonia gas from the reaction of aqueous Urea with liquid water is
spontaneous. (standard temperature is 25oC)
CO(NH2) 2 (aq) + H2O (l)  CO2 (g) + 2NH3 (g)
(13.4 kJ; no)
4. Using the values for standard entropy and standard enthalpy, determine whether the formation
of solid Ferric Oxide (iron ore) from the reaction of Iron and Oxygen gas is spontaneous.
(standard temperature is 25oC)
(-1483 kJ; yes)
EQUILIBRIUM CONSTANTS
NAME
1. Write the equilibrium constant expression for the following reactions:
a. 2 SO2 (g) +O2 (g) <==> 2 SO3 (g)
b. 4H2 (g) + CS2 (g) <==> CH4 (g) + 2 H2S (g)
2. One liter of a gas mixture at 100oC at equilibrium contains .0045 moles of dinitrogen tetroxide
and .030 moles of nitrogen dioxide. Calculate the equilibrium constant for the formation of
nitrogen dioxide from dinitrogen tetroxide. Are the products or reactants favored at equilibrium?
(.20; R)
3. The equilibrium constant for the decomposition of Bromine Monochloride gas into its elements is 11.1
and the equilibrium mixture contains 4.00 mol Chlorine gas. How many moles of Bromine gas and
Bromine Monochloride gas are present in the equilibrium mixture?
(4.00 mol, 1.20 mol)
4. Initially one mole of hydrogen and one mole of iodine are sealed in a 1 L flask and allowed to react
at 450oC. At equilibrium 1.56 mol of Hydrogen Iodide is present. Calculate the Keq for the reaction.
Are the products or reactants favored at equilibrium?
(48.6; P)
5. Determine the value for the equilibrium constant for the reaction 3A + B <==> 2C.
Initially 2 moles of A, 1.5 moles of B and .6 moles of C are placed in a 1 L vessel and allowed
to come to equilibrium. The final concentration of C is .95 moles.
(.21)
6. Determine the value for the equilibrium constant for the reaction A + 2B <==> 2C.
Initially 1.0 moles of A and 1.5 moles of B are placed in a 2.0 L vessel and allowed to come
to equilibrium. The equilibrium concentration of C is .35 mol/L.
(2.4)