Equilibrium and Solubility Assignment
1. Explain the difference between the rate of the reaction and the extent of
the reaction. (2 marks)
2. At equilibrium there is no overall change in the concentrations of
reactants and products. Why then is this considered a dynamic equilibrium?
(2 marks)
3. For a reaction that goes to completion, is Kc very large or very small?
Explain. (1 mark)
4. Water is boiling in a kettle at 100 oC. Is the system at equilibrium?
Explain.
(2 marks)
5. a) Explain how concentrations and K relate to equilibrium? (3 marks)
b) Explain why states are important to equilibrium problem solving. [2 marks]
6. What is the relationship between the equilibrium constant and the
forward and reverse reaction rates? (2 marks)
7. Why is the statement below incomplete? (1 marks)
‘” the Ksp for lead chloride is 2.2 x 10 10”
8. The decomposition of hydrogen peroxide produces water, oxygen and heat
( 6 marks) Predict the shift in equilibrium when:
A) more sodium oxide is added to the system
B) the temperature is increased
C) the pressure is increased
D) nitrogen gas is added
E) suggest two ways this equilibrium could be manipulated to maximize
sodium oxide formation.
9. What happens to the concentration of a Magnesium hydroxide in a
saturated solution when (5 marks)
a) more solute is added?
B) the solution is left to sit and the solvent
evaporates?
C) part of the solution is poured off?
D) sodium hydroxide is added
E) magnesium nitrate is added
10. The values of Ksp for binary ionic compounds that contain either sodium
or potassium are not listed in the Ksp table. Explain why.(2 marks)
11. Explain why there is no simple relationship between Ksp for a given
compound and the solubility of the compound in g/L. (2 marks)
12. Does a larger value of Ksp necessarily mean a greater solubility?
Demonstrate using silver chloride and silver bromate. (4 marks)
13. Consider a sample of water that possibly contains the following ions; Mg,
Pb 2+, Ba2+, and Ag1+. How would you identify which ion is present in the
solution based on your knowledge of solubility? Present your ideas as a flow
chart and write out the total and net ionic equations for each reaction. (8
marks)
14. Why can’t the solubility of barium carbonate be increased by adding
more barium carbonate solid to a saturated barium carbonate solution?
(2 marks)
15. Write the equilibrium expression for each of the following physical
changes. (3 marks)
A) evaporation of water
B) dissolving of calcium fluoride
C) sublimation of dry ice
Inquiry
1. A reaction mixture, 2NO(g) + O2 (g) <------> 2NO2 (g) contained 1.40 mol of
NO(g), 1.00 mol of O2 (g), and 0.900 mol of NO2 when at equilibrium in a 2.00
L bulb. How many moles of O2 (g) had to be added to the mixture to increase
the number of moles of NO2 to 1.10 when equilibrium is re-established?
2. A 0.521 mol sample of dinitrogen tetroxide is placed in a 1.00 L reaction
vessel and heated to 100 oC. At equilibrium it is found that 35.8% of the
dinitrogen tetroxide has decomposed to nitrogen dioxide. Calculate the Kc
at this temperature. (4 marks)
3. In an experiment at 240 oC , it was found that for the reaction
PCl3(g) + Cl2 (g) <------> PCl5 (g) equilibrium concentrations were 0.450 mol/L
PCl3(g), 0.320 mol/L Cl2 (g) , and 0.220 mol/L PCl5 (g).
A) Calculate Kc for the reaction at this temperature
B) If the volume of the reaction vessel is halved, calculate the new
concentrations once equilibrium is re-established. (7 marks)
4. At a certain temperature the Kc is 6.13 x 10-2 for the following
equilibrium:
2IBr (g) <---------> I2(g) + Br2(g)
A) When IBr is added to a reaction flask the system is allowed to
equilibrate. When the system equilibrates the bromine concentration is
0.0924 M. Determine the equilibrium concentrations of iodine and of IBr is
present. [4 marks]
B) What was the initial concentration of IBr placed in the reaction flask? [2
marks]
5. A) What are the equilibrium partial pressures of all gases when 1.00 atm
of H2O(g) is heated with coke to 900 K?
C(s) + H2O(g)
CO(g) + H2 (g) Keq = 0.45 at 900 K.
B) Determine which way the equilibrium will shift if 2.5 atm of water, 1.5
atm of carbon monoxide and 3.0 atm of hydrogen gas are placed in a reaction
vessel. [3 marks]
6. For the equilibrium, 2NO <---------> N2(g) + O2(g)
Kc= 0.185 @ 300K.
If 1.45 moles each of nitrogen and oxygen are placed in a 6.0 L reaction
flask and allowed to equilibrate, determine the equilibrium concentrations of
all chemicals present.
7.What is the solubility of ferric hydroxide in water at 25 oC in g/L. (4
marks)
8. Calculate the molar solubility of silver sulfate at 25 oC. (3 marks)
B) How many grams of silver carbonate are dissolved in 2500 mL of solution.
(4 marks)
C) What is the (m/v) percent of a saturated solution of plumbous chloride?
(4 marks)
9. Determine the concentration in ppm of Calcium ions present in a saturated
solution of 500.0 mL of calcium phosphate at 25 oC. (4 marks)
10. The maximum solubility of an ionic compound Aluminum hydroxide at 20
o
C is 1.3 g/L. Calculate the Ksp for Aluminum hydroxide (2 marks)
11. A solution of sodium chromate is added to a solution of silver nitrate
A) Complete a balanced chemical equation for what you expect to see
happen. (1 mark)
B) Determine the molar solubility of silver chromate. (3 marks)
C) Determine the solubility of silver chromate in 0.085 mol/L sodium
chromate.(5 marks)
12. One drop (.050 mL ) of 1.50 M potassium sulfate is added to 250 mL of
0.10 M barium chloride. Determine if a precipitate forms. (4 marks)
14. How many drops of 0.00010 mol/L calcium iodide solution will just begin
to precipitate lead iodide from 800.0 mL of a 0.90% (m/v) solution of
plumbic nitrate? (Assume that one drop equals 0.50 mL). (5 marks)
15. A solution of calcium chloride is made by dissolving 5.25 g in 600.0 mL.
If 10.48 mL of silver nitrate solution are required to titrate 25.0 mL of the
calcium chloride solution, what is the molar concentration of the silver
nitrate? (5 marks)
16. A 2.00 L solution contains the following nitrates as 0.10 M solutions; zinc,
calcium, silver, and lithium. If 0.05 mol/L sodium carbonate is added to the
solution, determine the order of precipitation. (8 marks)