Name: May 9, 2005
General Chemistry 1156 Final Exam
1. Give the IUPAC name for the following compounds. (6 pt.)
CH3 CH2 CH2 CH2 CH3 CH3 CH2 CH CH3 CH3 C CH3
2. From the following list, alkene, alkyne, halide, alcohol, aldehyde, ketone, carboxylic acid,
amine, amide, or ether, identify four functional groups in the compound below. (4 pt.)
H I NH2
Chem. 1156 Spring 2005 Final 1
3. Kinetic data for the following reaction was determined experimentally.
yY + zZ → products
Experiment Number Initial Concentration Initial Concentration Initial Rate of
(mol/L) [Y] (mol/L) [Z] Reaction (mol/L•s)
1 0.100 0.100 –5
2 0.200 0.100 –4
3 0.100 0.200 –5
a. Determine the rate law for the reaction. (4 pt.)
b. Determine the value of the rate constant. (2 pt.)
c. What is the overall order of the reaction? (1 pt.)
4. It takes 42.0 min for the concentration of a reactant in a first-order reaction to drop from 0.45
M to 0.32 M at 25°C. What is the half-life of the reaction? (3 pt.)
Chem. 1156 Spring 2005 Final 2
5. Use the following reaction to answer questions a-e.
2 HCl(g) + I2(s) 2HI(g) + Cl2(g) ∆H° = –47.8 kJ/mol Kc = 4.4x10–36 at 600. K
a. Write the expression for Kc and Kp (2 pt.)
b. Calculate the value of Kp? (2 pt.)
c. If Q = 20.0, what must happen for the reaction to reach equilibrium? (Do more reactants have
to be converted to products or products into reactants?) (1 pt.)
d. Are reactants or products more plentiful at equilibrium? (1 pt.)
e. Determine the effect on the equilibrium (circle one of the following: shift left, no change,
shift right) when the following changes take place. (5 pt)
Decrease the volume Shift left No Change Shift right
Increase the temperature Shift left No Change Shift right
Adding Cl2(g) Shift left No Change Shift right
Removing HCl(g) Shift left No Change Shift right
Add a catalyst Shift left No Change Shift right
Chem. 1156 Spring 2005 Final 3
6. A mixture of 5.0 moles of N2 and 5.0 moles of O2 is placed in a 1.00 liter container at a
given temperature and allowed to reach equilibrium according to the following equation.
Calculate the concentrations of all species present at equilibrium. (6 pt)
N2(g) + O2(g) 2NO(g) Kc = 100
Chem. 1156 Spring 2005 Final 4
Acids and Bases
7. Circle the one in each pair below that would be a stronger acid. (4 pt.)
a. H2SeO3 H2SeO4
b. HBrO2 HIO2
c. H2O H2S
d. NH3 AsH3
8. In the reaction below, label the acid (A), the base (B), the conjugate acid (CA), the conjugate
base (CB). (4 pt.)
CH3– + NH3 → CH4 + NH2–
9. Indicate in the example below which is the Lewis acid (LA) and which is the Lewis Base
(LB). (2 pt.)
NH3 + AlCl3 → NH3AlCl3
Chem. 1156 Spring 2005 Final 5
10. Of the following six (a-f) aqueous equilibrium problems, attempt to solve four (4), and only
four. (9 pt. each, total of 36 pt.)
a. Calculate the pH of a 0.020 M telluric acid solution, H2TeO4, that has the stepwise
dissociation constants of Ka1 = 2.1x10 , and Ka2 = 6.5x10 .
What is the concentration of TeO42– at equilibrium?
b. The pH of 0.10 M C4H9NH2(aq), butylamine, was measured as 11.84. What are the values
of Kb and pKb of butylamine?
Chem. 1156 Spring 2005 Final 6
c. The pH of a 0.15 M solution of NaZ (the sodium salt of HZ) is 10.7. What is the Ka for HZ?
d. What is the pH of a solution prepared by dissolving 0.35 mol of solid NaF in 1.00 L of 1.1 M
HF. Ka = 7.1x10 for HF.
Compare the % dissociation of HF in the buffer and that of 1.1 M HF (using calculations).
Chem. 1156 Spring 2005 Final 7
e. The solubility of AuCl3 (as Au3+ and Cl–) in water at 298 K is 3.3x10–7 M. What is Ksp for
f. The Ksp of Ag2S is 1.0x10–51. What is the molar solubility of Ag2S?
11. Which of the following compounds will be more soluble in acidic solution than in water?
(a) Ag2S (b) Ag2CO3 (c) SnI2
Chem. 1156 Spring 2005 Final 8
Thermodynamics and Electrochemistry.
12. The entropy change on vaporization (∆Svap) of a compound or element is: (1 pt)
A. always negative.
B. always positive.
C. sometimes is positive and sometimes is negative.
13. Hydrogen peroxide (H2O2) decomposes according to the equation
H2O2(l) → H2O(l) + (1/2)O2(g).
Calculate K for this reaction at 25°C. (∆H° = −98.2 kJ/mol, ∆S° = 70.1 J/K·mol) (3 pt)
Chem. 1156 Spring 2005 Final 9
Consider the following electrochemical cell: Zn(s) | Zn2+(aq) || Ag+(aq) | Ag(s)
14. Identify the anode and cathode compartments. (2 pt)
15. Calculate the cell potential, at 25°C, given the following reduction potentials (3 pt)
Ag+(aq) +e– → Ag(s) +0.80 V
Zn2+(aq) + 2e– → Zn(s) –0.76 V
16. Calculate ∆G° for the reaction. (3 pt.)
17. Calculate the equilibrium constant, K, for the reaction. (2 pt.)
Chem. 1156 Spring 2005 Final 10