Name _____________________
CHEM 1364
Test #3
Spring 2013 (Buckley)
1. (5 points) Give the oxidation number for the underlined atom in each of the species
below.
a. CH4
______
b. NO2-
______
c. Ca(NO3)2
_______
d. I2
_______
e. SeO42-
_______
2. (4 points) Circle the element (will be only one symbol) that is oxidized in each of the
following equations.
Br2 (ℓ) + 2 K (s) 
2 KBr (s)
3 Fe(NO3)2 (aq) + 2 Al (s)  3 Fe (s) + 2 Al(NO3)3 (aq)
P4 (s) + 10 HClO (aq) + 6 H2O (ℓ) 
Cl2 (aq) + 2 NaBr (aq) 
4 H3PO4 (aq) + 10 HCl (aq)
2 NaCl (aq) + Br2 (aq)
3. (4 points) Based on the activity series attached, indicate whether each of the following
reactions would occur or not by writing “Yes” on the line if it would occur and “No” if it
would not.
Ca (s) + NiCl2 (aq) 
Sn (s) + MnCl2 (aq) 
CaCl2 (aq) + Ni (s)
SnCl2 (aq) + Mn (s)
_______________
_______________
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4. (8 points) Consider the following molarity problems. Show your work to receive any
partial credit at all.
a. How many moles of CaBr2 are contained in 45.67 mL of 0.054 M CaBr2 solution?
b. 15.5-g of Ba(NO3)2 are dissolved in 500 mL of solution. What is the molarity of
Ba(NO3)2 in the solution?
c. What is the molarity of nitrate ion in the solution of part b?
d. What volume of 0.432 M NH4Cl would be required to obtain 15.0-g of NH4Cl?
e. 75.0 mL of a solution that is 0.234 M in KCl is diluted to a total volume of
250.0mL. What is the concentration of the diluted solution?
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5. (7 points) Consider the following chemical equation. Again, show your work.
NaCl (aq) + Pb(NO3)2 (aq) 
NaNO3 (aq) + PbCl2 (s)
a. Balance the equation.
b. How many moles of Pb(NO3)2 would be required to react with 35.00-mL of
0.134 M NaCl?
c. How many grams of PbCl2 could be formed by the reaction of 35.00-mL of
0.134 M NaCl assuming it is the limiting reactant?
d. What is the percent yield in the reaction from part c if 0.545-g of PbCl2 are
actually formed?
6. (4 points) Consider the following energy situations. Find ΔE in each case.
a. 45 J of work are done on a system and 100 J of heat are removed.
b. 65 J of work are done by a system and 200 J of heat are added.
c. No work is done on a system in an insulated container.
d. 55 J of work is done on a system and 250 J are added.
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7. (3 points) How much heat is required to increase the temperature of 50.0-g block of zinc
from 35 ºC to 80 ºC? The specific heat capacity of zinc is 0.39 J/g-ºC. Show your work.
You will find a potentially useful equation on page 6.
8. (5 points) A 65.0-g sample of water cools from 85 ºC to 45 ºC. If the heat removed from
this water were placed into cold water, what mass of cold water would be required for its
temperature change to be 15 ºC? The specific heat capacity of water is 4.18 J/g-ºC.
Show your work. You will find a potentially useful equation on page 6.
9. (6 points) Using Hess’s Law, calculate the enthalpy change for the reaction:
Fe2O3 (s) + 3 CO (g)

2 Fe (s) + 3 CO2 (g)
given the information below:
CO (g) + 1/2 O2 (g)  CO2 (g)
ΔHº = -824 kJ
2 Fe (s) + 3/2 O2 (g) 
ΔHº = -283kJ
Fe2O3 (s)
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10. (8 points) Consider the following reaction:
2 H2S (g) + 3 O2 (g)

2 H2O (ℓ)
+ 2 SO2 (g)
a. What is the enthalpy change for the reaction using
the data in the table to the right?
Species
H2S (g)
O2 (g)
H2O (ℓ)
SO2 (g)
ΔHfº (kJ/mol)
-20
0
-286
-296
b. Is the reaction exothermic or endothermic?
c. How much heat is given up or absorbed if 25.0-g of H2S goes through this
combustion process? Please indicate whether the heat is given up or absorbed.
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q = Cs × m × ΔT
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