CHEM 101—General Chemistry
Final Exam
9 December 2002
Name ________________________
h = 6.626 x 10-34 J s
k = 1.381 x 10-23 J K-1
c = 3.00 x 108 m s-1
g = 9.807 m s-2
R = 8.314 J mol-1 K-1
e = 1.602 x 10-19 C
RH = 1.097 x 10-7 m-1
1. (10 points) A 1.00” x 2.00” x 12.0” piece of seasoned ebony wood weighs 436.6 g. Will it
float in water (H2O = 1.0 g mL-1)?
2. (20 points) Water ice at –25 oC has a density of 0.917 g mL-1. If 10.0 mL of ice at this
temperature is heated to a final temperature of 150 oC and evaporated, determine the final
volume of the water if the pressure if 743 Torr.
3. (20 points) For the reaction
N2O4(l) + 2 N2H4(l) 3 N2(g) + 4 H2O(g)
how many grams of N2H4 are required to react completely with 25.49 g N2O4?
4. (10 points) What is the preferred oxidation state of phosphorous (P) when it forms an anion?
5. (10 points) Give half-reaction for the oxidation and reduction processes and a balanced net
ionic equation for the following redox reaction:
H2(g) + Hg2Cl2(s) H+(aq) + Hg(l) + Cl-(aq)
6. (20 points) Iodine (I2) is a solid at room temperature but sublimes easily (goes from solid to
gas phase). It requires 246.0 J of energy to vaporize 1.000 gram of I2. If I2 is irradiated
with 510 nm light, how many photons are required to vaporize this 1.000 g of I2?
7. (20 points) 27.81 mL of phosphoric acid, H3PO4, is titrated using 0.5017 M potassium
hydroxide, KOH. The end-point of the titration is reached when 43.90 mL of KOH have
been added. Determine the concentration of phosphoric acid.
8. (10 points) Give the electron configuration of Sn2+:
9. (10 points) Draw the Lewis dot structure of acetone, CH3C(O)CH3: (C atoms are connected
in a line; central C atom bonded to O atom)
10. (10 points) Draw the electron energy diagram of an excited oxygen atom.
11. (10 points) Which of the following is the correct order of increasing (smallest to largest)
atomic radii:
a. Br, F, S, As
b. S, As, Br, F
c. F, S, Br, As
d. F, Br, As, S
12. (10 points) Which species has a greater ionization energy: Ne or Na+? Explain why.
13. (10 points) Draw the Lewis dot structure of carbon monoxide, CO.
14. (20 points) Explain the why ionization energies decrease as one goes down a specific
column in the Periodic Table.
15. (10 points) Hypochlorous acid has the chemical formula HOCl. Which of the following
structures would you expect to be the actual structure of the molecule:
Cl – H – O
Cl – O – H
O – Cl – H