Chem 1711
Name ___________________________________
Quiz 3
1.
September 30, 2014
Aqueous solutions are prepared using three solutes X, Y, and Z; descriptions of each solute follow:
X is a weak acid
Y is a water-soluble ionic compound
Z is a water soluble molecular compound
Put the solutions X (aq), Y (aq), and Z (aq) in order of increasing ability to conduct electricity.
____________ < ____________ < ____________
least conductivity
most conductivity
2.
36.024 g iron (III) sulfate (Fe2(SO4)3 molar mass = 399.9 g/mol) is dissolved in water resulting in a 500.0 mL solution.
a.
Identify the solute and the solvent in this solution.
b.
Which of the following is the best description of the numbers and identity of particles in this solution? Circle the
letter of the one best answer below.
c.
solute ___________________ solvent __________________
A. 2 Fe3+ + 3 S2– + 12 O2–
B. 3 Fe2+ + 2 SO43–
C. Fe2(SO4)3
D 2 Fe + 3 S + 12 O
E. 2 Fe3+ + 3 SO42–
F. none of these
Determine the molar concentration of this solution.
[Fe2(SO4)3] = __________________
d.
Determine the molarity of sulfate ions in this solution.
[SO42–] = __________________
3.
a.
Determine the volume (in mL) of 6.85 M H3PO4 (aq) that would be required in a dilution procedure to prepare 1.25 L
of 0.775 M phosphoric acid.
___________________ mL
b.
Now consider that 20.00 mL of the dilute acid from part a above is transferred to a 100 mL volumetric flask, and
water is added until the final solution volume is 100.0 mL. Determine the concentration of this final, dilute solution.
[H3PO4] = ___________________
4.
5.
What are the units of molar concentration (or molarity)? Circle the one best answer below.
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Circle all of the compounds below that you would expect to be soluble in water.
NiCO3
6.
AgC2H3O2
KOH
NH4Cl
PbBr2
BaSO4
Consider the following reaction: PbS (s) + 4 H2O2 (aq)  PbSO4 (s) + 4 H2O (l).
Determine the volume (in mL) of 0.400 M H2O2 (aq) required to react with excess PbS to yield 16.24 g PbSO4 (molar
mass = 303.3 g/mol). Assume that the reaction goes to completion.
___________________ mL
7.
8.
Predict the products that will form when aqueous solutions of the following reactants are combined. Give the chemical
formulas and physical states of the products, then balance the equation. If no reaction will occur, write No Reaction.
a.
_______ FeSO4 (aq) + _______ AgNO3 (aq)  _______________________ + _______________________
b.
_______ NaCl (aq) + _______ K2C2O4 (aq)  _______________________ + _______________________
Consider the following reaction: 2 Na3PO4 (aq) + 3 Ca(OH)2 (aq)  Ca3(PO4)2 (s) + 6 NaOH (aq)
a.
Identify the precipitate in this reaction.
__________________________
b.
Write the net ionic equation for this reaction. Be sure to include all physical states and charges on ions.
c.
Calculate the volume (in mL) of 0.750 M Na3PO4 (aq) required to react completely with 65.0 mL of
0.500 M Ca(OH)2 (aq).
___________________ mL
9.
Consider again the reaction between solutions of sodium phosphate and calcium hydroxide (see #8 above). If 50.00 mL
of 0.206 M Na3PO4 (aq) is combined with 50.00 mL of 0.411 M Ca(OH)2 (aq), identify the limiting reactant.
__________________________
Chem 1711
Name ___________________________________
Quiz 3
1.
2.
3.
September 30, 2014
What are the units of molar concentration (or molarity)? Circle the one best answer below.
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!"# !"#$%&
!"# !"#$%&"'
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Predict the products that will form when aqueous solutions of the following reactants are combined. Give the chemical
formulas and physical states of the products, then balance the equation. If no reaction will occur, write No Reaction.
a.
_______ NaCl (aq) + _______ K2C2O4 (aq)  _______________________ + _______________________
b.
_______ FeSO4 (aq) + _______ AgNO3 (aq)  _______________________ + _______________________
Aqueous solutions are prepared using three solutes X, Y, and Z; descriptions of each solute follow:
X is a water soluble ionic compound
Y is a water soluble molecular compound
Z is a weak acid
Put the solutions X (aq), Y (aq), and Z (aq) in order of increasing ability to conduct electricity.
____________ < ____________ < ____________
least conductivity
most conductivity
4.
a.
Determine the volume (in mL) of 6.85 M H3PO4 (aq) that would be required in a dilution procedure to prepare 2.50 L
of 0.975 M phosphoric acid.
___________________ mL
b.
5.
Now consider that 20.00 mL of the dilute acid from part a above is transferred to a 100 mL volumetric flask, and
water is added until the final solution volume is 100.0 mL. Determine the concentration of this final, dilute solution.
Circle all of the compounds below that you would expect to be soluble in water.
NH4Cl
6.
PbBr2
BaSO4
NiCO3
[H3PO4] = ___________________
AgC2H3O2
KOH
Consider the following reaction: PbS (s) + 4 H2O2 (aq)  PbSO4 (s) + 4 H2O (l).
Determine the volume (in mL) of 0.400 M H2O2 (aq) required to react with excess PbS to yield 46.41 g PbSO4 (molar
mass = 303.3 g/mol). Assume that the reaction goes to completion.
___________________ mL
7.
76.875 g iron (III) sulfate (Fe2(SO4)3 molar mass = 399.9 g/mol) is dissolved in water resulting in a 500.0 mL solution.
a.
Identify the solute and the solvent in this solution.
b.
Which of the following is the best description of the numbers and identity of particles in this solution? Circle the
letter of the one best answer below.
c.
solute ___________________ solvent __________________
A. 2 Fe3+ + 3 S2– + 12 O2–
B. 2 Fe3+ + 3 SO42–
C. Fe2(SO4)3
D 2 Fe + 3 S + 12 O
E. 3 Fe2+ + 2 SO43–
F. none of these
Determine the molar concentration of this solution.
[Fe2(SO4)3] = __________________
d.
Determine the molarity of sulfate ions in this solution.
[SO42–] = __________________
8.
Consider the following reaction: 2 Na3PO4 (aq) + 3 Ca(OH)2 (aq)  Ca3(PO4)2 (s) + 6 NaOH (aq)
a.
Identify the precipitate in this reaction.
__________________________
b.
Write the net ionic equation for this reaction. Be sure to include all physical states and charges on ions.
c.
Calculate the volume (in mL) of 1.063 M Na3PO4 (aq) required to react completely with 82.5 mL of 0.780 M
Ca(OH)2 (aq).
___________________ mL
9.
Consider again the reaction between solutions of sodium phosphate and calcium hydroxide (see #8 above). If 50.00 mL
of 0.411 M Na3PO4 (aq) is combined with 50.00 mL of 0.560 M Ca(OH)2 (aq), identify the limiting reactant.
__________________________