Equilibrium Worksheet
Name_________________________________
1. Write the expression for the equilibrium constant for the following:
2N2O5(g) + 6kJ ⇄ 4NO2(g) + O2(g)
2. Calculate the equilibrium constant for the reaction in problem 1 if the equilibrium concentrations are [N2O5] =
0.50 mol/L, [NO2] = 0.80 mol/L, [O2] = 0.20 mol/L.
Are products or reactants favored?
3. In what direction would the equilibrium position shift for the equation in problem 1 by
a. An addition of O2 to the reaction vessel?
b. A decrease in the pressure?
c. An increase in temperature?
4. The equilibrium constant, Keq = 5.6, for the following reaction: 2NO2(g) ⇄ N2O4(g) In a one-liter container,
the amount of N2O4, at equilibrium, is 0.66 mol. What is the equilibrium concentration of NO2?
Are products or reactants favored?
5. What is the equilibrium constant for the following reaction if the equilibrium concentration of CO is 0.1M and of
CO2 is 0.005M?
CO2(g) + C(s) ⇄ 2CO(g)
Are products or reactants favored?
6. What effect would an increase in pressure have on the equilibrium position of the following reaction:
SO2(g) + NO2(g) ⇄ SO3(g) + NO(g)
7. Which value of Keq indicates most favorably for product formation Keq = 1 x 1012, Keq = 1.5, or Keq = 5.6 x 10-4?
8. Hydrogen sulfide gas decomposes into its elements and establishes and equilibrium at 1400˚C
2H2S(g) ⇄ 2H2(g) + S2(g)
A liter of this gas mixture contains 0.18 mol H2S, 0.014 mol H2, and 0.035 mol S2. Calculate the equilibrium
constant, Keq, for this reaction.
Are products or reactants favored?
9. A mixture at equilibrium at 827˚C contains 0.552M CO2, 0.552M H2, 0.448M CO, and 0.448 M H2O. The balanced
equation is CO2(g) + H2(g) ⇄ CO(g) + H2O(g)
What is the value of Keq?
Are products or reactants favored?
10. The value of Ksp indicates how water soluble a salt iis. The Ksp at 20oC for AgCl is 1.7 X 10-17, while the Ksp for AgBr
is 5 X 10-13. Which is the more water soluble salt?
11. Consider this equation: AgBr(s) ⇄ Ag+ (aq) + Br-(aq)
A saturated solution of silver bromide, AgBr, has a silver ion concentration of 7.1X 10-7M. What is the value of
the solubility product, Ksp for silver bromide? (Hint: for every silver ion formed, a bromide ion is formed, so if
you are given the concentration of silver ions, you were also given the concentration of bromide ions)
12. In a saturated solution of Pb3(PO4)2, the [Pb2+] is 0.1M and the [PO4 3-] is 0.01M. a) Write the balanced reversible
chemical equation for the dissolving of lead(II)phosphate. b) Then write the solubility product expression and
finally calculate the Ksp of Pb3(PO4)2 .
Answers:
2) Keq = .33 ; reactants
4) [NO2] = .34M ; products
5) Keq = 2 ; products 8) Keq = 2.1 X 10-4 ; reactants
9) Keq = .659 ; reactants
11) Ksp = 5.0 × 10-13
12) Ksp = 1 × 10-7