Chemistry
CH 13 HC Solutions Worksheet 2
1. A 455-mL sample of 3.0 M lead (II) nitrate solution is mixed with an equal volume
of 3.0 M potassium iodide solution.
a. Write the net ionic equation.
b. Identify the spectator ions
c. Calculate the mass of precipitate produced in this reaction. (316.0g)
d. Is there an “excess reactant?” If so, what is it and how many moles remain
after the reaction is complete? (.685n)
e. What is the molarity of the remaining ions after mixing. (K 3.01M, NO3
3.01M, Pb 0.75m)
2. If 44.7 grams of lead (II) iodide are precipitated from the reaction of 120.0 mL
of 1.0 M lead (II) nitrate solution and 275.0 mL of potassium iodide solution, what is
the molarity of the potassium iodide solution? (Assume both reactants are
completely used up in the reaction). (0.705M)
3. What is the boiling point elevation of water for a solution that contains 125 g of
barium nitrate dissolved in 500.0 ml of water. (1.46C)
4. Write the net ionic equation showing the dissolution of the following compounds:
a. Na3PO4 (s) (Na3PO4 (s) = 3Na+ + PO4-3)
b. iron III sulfate (s)
c. Mg(CH3CO2)2 (s)
d. aluminum sulfate (s)
5. The following solutions are combined in a beaker, NaCl, Na3PO4, and Ba(NO3)2
a. Will a ppt form and if so write the formula.
b. List all spectator ions present in the system.
6. It is possible to have spectator ions present in many chemical systems, not just in
precipitation reactions . Ex. Al(s) + HCl (aq) = AlCl3 (aq) + H2 (g) unbalanced
a. Virtually every HCl molecule is ionized. True or False.
b. There is only one spectator ion in this system, name it.
c. Write the balanced equation.
d. If 9.0 g of Al react in the equation above, what volume of gas at STP will be
produced. (11.2L)
7. Predict the boiling points of the following
a. 0.200 m solution of glucose in water. (100.102C)
b. 0.200 m solution of potassium iodide in water. (100.204C)
8. A chief ingredient of antifreeze is liquid ethylene glycol C2H4(OH)2. Assume
C2H4(OH)2 is added to a car radiator that holds 5.0 kg of water.
a. How many moles of C2H4(OH)2 should be added to the water to lower the
freezing point of water to -18.0 C (48.39n)
b. How many grams of C2H4(OH)2. (3.00 x103g)
c. C2H4(OH)2 has a density of 1.1 kg/L. How many liters of C2H4(OH)2 should be
added to the water to protect the system to -18.0 C (2.73L)
9. 12.0 g of an unknown compound, a nonpolar nonelectrolyte, is dissolved in
100.0 g of melted camphor. The resulting solution freezes at 99.4 C. Camphor
F.P. = 178.4 C Kf = -40.0
a. How many degrees did the freezing point of camphor change. (7.9 C)
b. What is the molality of the solution of camphor and the unknown based
on the freezing point data. (1.98 n/kg)
c. What is the molar mass of the unknown. (60.76 g/n)
10. A solution is prepared by dissolving 75.00 g of Ca3(PO4)2 in 550.0 ml of water.
Calculate the freezing and boiling points of this solution. (-4.09C, 101.12C)
11. Match the following
____ an ionic compound that is quite soluble in water
____ an ionic compound that is not very soluble in water
____ a molecular compound that ionizes in water
____ a molecular compound that does not ionize in water
a. HCl
b. BaCl2
c. AgCl
d. CCl4
12. How many grams of CH3OH should be added to 200. g of acetic acid to lower its
freezing point by 2.50 C. What would be the new boiling point of acetic acid if
you added 35.0 g of CH3OH to 200. g of acetic acid. (4.10g, 135.3C)
13. Determine which of the following combinations of solutions will
produce a precipitate:
Write the net ionic equation for each ppt reaction.
a. KCl + Ca(NO3)2
b. Na2SO4 + BaCl2
c. (NH4)2CO3 + Cd(NO3)2
d. NH4Cl + Na2SO4
e. Ca(NO3)2 + CuCl2
14. A solution is made by mixing 550.0 ml of 0.650 M Na2SO4 with 500.0 ml of
0.355 M Na3PO4. Calculate the molarity concentration of each ion in solution.
(Na 1.19M, SO4 0.340M, PO4 0.169M)
15. If the mass percent of a CaCl2 solution is 35.5 % in 500.0 ml of water, calculate
the mass (g) of the solute added and both the freezing point and boiling point of
this solution. What is the mole fraction of this solution. (275.2g, -27.68C,
107.59C, 8.19%)
16. The freezing point of a solution is lowered 2.89 C when the solute concentration
is 1.03 m. What is Kf. (-2.81)
17. How many NH4+ ions are present in 1.25 L of 0.400 M (NH4)3PO4 solution.
(9.03x1023ions)
18. An ionic solid dissolves in water. The temperature of the solution drops 10.0 C.
Is the dissolving process for this substance endothermic or exothermic.
19. How many mL of a 0.250 M HCl solution would contain 3.00 g of pure HCl.
(328.8mL)
20. Given 150. mL of 0.250 M NH4OH is mixed with 125 mL of 0.400 M Al(NO3)3
a. Write the balanced chemical equation.
b. Write the ionic equation.
c. Write the net ionic equation
d. Identify spectator ions and the insoluble product.
e. Find the maximum precipitate that could be produced. (0.975g)
f. Determine the moles of excess reactant remaining. (0.0375n)
21. Concentrated nitric acid is 70.4% HNO3 by mass. What is the mole fraction of
this compound. (40.6%)
22. Concentrated phosphoric acid is 85.0 % by mass H3PO4. If the molarity of
concentrated H3PO4 is 14.5 n/L, what is the density. (1.42g/mL)
23. At what temperature will a mixture of 20.0 g of NaCl and 500.0 g of water boil.
(100.697 C)
24. A solution is prepared by dissolving 8.50 g of an unknown nonelectrolyte in
0.250 kg of water. If the freezing point of the water lowers to -0.724 C, what is
the molar mass of the solute. (87.36g/n)
25. A aqueous solution made up of 32.47 g of iron III chloride in 100.0 mL of
solution has a density of 1.249 g/mL. Calculate molarity, molality, freezing
point, and percent mass of this solution (2.0M, 2.16n/kg, -16.07C, 104.41C)