CHEM 1143 General Chemistry I
Examination IIIName:______
Answer each of the following questions on the scantron. True is A, False is B; others answer as labeled.
1. T or F (a or b) on scantron to indicate the statement is true or false:
T F / The following set of quantum numbers is acceptable for an electron in an atom: n=3, l=2, ml = 2 ms = +1/2T F / There are at most 6 electrons that can have a value of n=2 for a given atom
T F / The carbon atom in its lowest electron configuration has two electrons with the same spin value in its outermost subshell.
T F / The first ionization energy of Be is greater than that for B
T F / As a general rule, the atomic radii of neutral atoms decrease as you move across a given row of the periodic table.
Multiple Choice.
2. Light of wavelength equal to 3.45 x 10-6meters is used in a special chemistry
experiment. What is the frequency of this light in Hertz?
a. 1.15 x 10-16 b. 8.70 x 1013 c. 2.90 x 105 d. 4.35 x 1012
3. An atom relaxes from a higher state to a lower state and as a result, light of
Wavelengthequal to 568 nm is given off. What is the difference in energy in J
between the two states?
a. 3.50 x 10-19 b. 1.26 x 1048 c. 7.97 x 1047 d. 3.76 x 10-22
4. Which of these has the greatest atomic radius?
a. K+ b. Ca2+ c. Cl- d. Li+
5. The l quantum number can have values of 0, 1, 2, etc. corresponding to s, p,
d, etc.What does this quantum number describe about the electron orbitals in
the atom?
a. energy b. shape c. orientation d. spin
Open Questions. Write and indicate your solution for each problem.
12. Draw the complete electron configuration for the following species
Mg2+Si
Cr
Cu
Na+
13. List these in order of increasing atomic radius: Sr F Sb P
14. List these in order of increasing first ionization energy: C N O F
15. Calculate the wavelength, in nanometers, of a photon that will excite an
electron in a hydrogen atom from the n=2 to the n=4 energy level.
16. For the element Co: From which level and which sublevel will the third
electron be ionized from Co?
17. In an experiment liquid hexane, C6H14 (l) is combusted completely to produce
CO2(g) and H2O (l) according to the equation:
2 C6H14 (l) + 19 O2(g) 12 CO2(g) + 14H2O (l)
The Ho for the reaction is -8.39 x 103 KJ. Calculate Hof for C6H14 (l).
18. / Given the following data:H (kJ)
2O3(g) 3O2(g) / - 427
O2(g) 2O(g) / 495
NO(g) + O3(g) NO2(g) + O2(g) / - 199
calculate H for the reaction
NO(g) + O(g) NO2(g)
19. / a. Write a balanced equation for the combustion of benzene, C6H6(l) in oxygen.
b. The standard heat of combustion of benzene is -3271 kJ/mol. Calculate its standard heat of formation, Hf , given the data:
Hf [CO2(g)] = -394 kJ; Hf [H2O(l)] = -286 kJ