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SCHM 109 Study Guide Exam 3
Spring 2015
I am starting out this study guide with a list to remind you of some topics we have covered.
1. About hemoglobin -what is its structure and what is its role in the body? How does the charge of the Fe
in hemoglobin affect its activity? What are some of the problems in the inherited blood disorders referred to
as methemoglobinemia.
2. What is a solution, solute, solvent?
3. What do the following mean? Saturated solution, miscible, “like dissolves like”, electrolyte
4. Calculating concentrations % (w/v) and molarity (Worksheet N1.)
5. Molarity and titration problems. See worksheet N2.
6. Using the dilution equation. See worksheet O.
7. Temp effects on solubility and pressure effects on gas solubility
8. Determine the relative solubility of several compounds and explain reasoning (having to do with polarity
of molecules and/or the ability to hydrogen bond.) (Parts of Worksheet I 2.)
9. Pictures of the hydrogen bonding in water, or of ionic compounds or polar compounds dissolved in water.
(See worksheet I 3.)
10. ∆G = ∆H-T∆S. What is the sign of ∆G for a process that proceeds in the forward direction (for a
chemical reaction this could be termed product favored.) What aspect of a process does ∆H deal with? ∆S?
11. Reaction progress diagrams!
12. Kinetics. Rates. Rate laws. Rate constants. How are rate constants and activation energy related? How
does a catalyst affect the rate?
13. Requirements for a reaction to occur.
14. What is going on at equilibrium in a chemical reaction? How is Keq defined? Be able to write an
equilibrium constant expression for a reaction. Be able to use an equilibrium constant expression
mathematically. How are Keq and ∆G related?
15. Know how a Brǿnsted-Lowery acid and base are defined. From a reaction between an acid and base, be
able to write the conjugate acid and base. (See Worksheet Q.)
16. What is a Ka. Be able to write a Ka for a given acid. How does the size of Ka relate to acid strength?
17. Be able to calculate the concentration of H3O+ from OH- concentrations and vice versa.
SCHM 109 Study Guide Exam 3
Show logic and calculations for all problems. Remember to include units and be careful with sig. fig..
You will be given a periodic table, electronegativity table, the charges on some polyatomic ions and
transition metal ions, and the following supplementary information.
Equations for temperature: F = 1.8 C + 32
K = C + 273.15
English to metric conversions
Length 1 m = 39.47 in
Mass 1 kg = 2.205 lb
Volume 1 L = 1.057 qt
1 in = 2.54 cm
1 lb = 453.5 g
R = 0.08205 (LatmmolK)
1 atm = 760. 0 mm Hg
Examples of possible questions you might find on the test (It is not meant to include all possibilities.)
1. Briefly describe a human genetic disease based on oxidation-reduction chemistry of hemoglobin.
A full credit answer should include one or more equations for chemical reactions.
2. What is the concentration in molarity units of a solution that has 7.00 g of NaCl dissolved in water to give
520.6 mL of solution?
3. If 83.00 mL of a 3.075 M solution of NaOH is diluted to a final volume of 12.88 L, what will its
concentration be?
4. Based on the following reaction, HCl + NaOH  H2O + NaCl, determine the concentration of
hydrochloric acid, HCl, if 10.00 mL of acid required 15.51 mL of 0.2500 M NaOH to reach the endpoint of
the titration.
5. What volume of a 15% (w/v) solution of LiOH would be produced if you used 8750 g of LiOH?
6. Which of the following compounds would you predict to have the highest, intermediate, and lowest
solubility in water? Explain your answer, using structures where appropriate.
H
H
H
a.
C
C
H
C
C
O
b.
H
H
H
H
H
H
H
7. For salt X, determine how much
will remain undissolved if 500 g is
mixed into a liter of pure water at 65 °C.
H
H
C
O
H
H
C
H
c.
C
C
H
H
H
C
H
H
Solubility of Salt X in Water at Different Temp.
Grams of salt Dissolved per Liter of H2O
H
160
140
120
100
80
60
40
20
0
15
25
35
45
Temp oC
55
65
75
8.a) Determine whether the following would be more soluble in water or CCl4.
i) CH3CH3
ii) HCl
iii) NaCl
iv) I2
v) Na3PO4
b) Which of the following are strong electrolytes, weak electrolytes or non-electrolytes?
i) CH3COOH (acetic acid)
ii) HCl
iii) CH3CH2OH (ethanol)
iv) NaCl
9. Given the reaction between Fe3+ with I- :
2 Fe3+ (aq) + 2 I- (aq)  2 Fe2+ (aq) + I2 (aq)
a) Write a general rate law for the reaction.
b) Use the experimental data, which looks at initial rates to produce
I2, to calculate a rate for the reaction.
Initial Rate Data
Time (s)
Conc. of I2 (M)
10
3.23 x 10-3
20
6.42 x 10-3
30
9.59 x 10-3
40
1.31 x 10-2
50
1.66 x 10-2
10. a) In a reaction between NO and O2 to form NO2, the rate law was found to be Rate = 1.45
x104[NO]2[O2]. Determine the initial rate of the rxn. when 0.035 M NO reacts with 0.027 M O2.
b) If for this same reaction, the rate was found to be 0.26 M/s when O2 was 0.018 M, what was the
concentration of NO?
c) In a kinetics experiment, if I told you that the value of k that you obtained is relatively large, what height
hill should be drawn for this reaction on a reaction progress diagram (vertical axis = G°).
11. Explain how/why changes in temperature result in changes in a rate constant, k. As part of your
explanation, include an appropriate graph.
12. Write equilibrium constant expressions for the following reactions:
a) 2 H2 (g) + 2 NO (g)  2 H2O (g) + N2 (g)
b) Fe (s) + CO2 (g) 
FeO (s) + CO (g)
13. Shown below is a balanced equation for the decomposition of H2S to form H2 and S2.
2 H2S (g)  2 H2 (g) + S2 (g)
a) Write an equilibrium constant expression for the reaction.
b) Given the equilibrium concentrations: [H2S] = 0.1007 M, [H2] = 0.0219 M, and [S2] = 3.30 × 10-3 M,
calculate the numerical value of Keq.
c) Assume the equilibrium is perturbed. When equilibrium is reestablished, the following concentrations
are observed: [H2] = 0.00287 M and [S2] = 0.171 M. Calculate [H2S] under these new conditions.
d) What can you say about the forward and reverse reaction rates when the system is at equilibrium?
e) How is Keq defined? (I am not asking you to write an equilibrium constant expression using
concentrations.)
14 a) Qualitatively, for the reaction shown in the previous question, would the ∆G° value be positive or neg.?
Explain your logic.
b) Assuming I told you the reaction in in the previous question, was relatively fast. Draw a reaction
coordinate diagram that describes that system. Then draw another showing how the system would be
changed in the presence of a catalyst. Be sure to clearly label all important quantities that we have discussed
in lecture.
15. What is the definition of a Brønsted-Lowry acid?
16. Identify the acid and base on the reactant side of the equation shown below. Predict the products
of the reaction and indicate the conjugate of each reactant.
NH3 + HBr 
17.(a) Write a balanced chemical reaction for the dissociation of acetic acid (CH3COOH) in water, and then
(b) write the Ka expression for that rxn. Acetic acid is a relatively weak acid. (c) Would formic acid
dissociate to a greater or lesser extent in water compared to acetic acid? (d) Which acid would have the
larger Ka.
18.(a) Calculate the [H3O+] of a solution that contains an [OH-] = 7.00 x 10-3 M solution. Is this solution
acidic, neutral or basic?