n
2
E = RH(
1
2
ni
1f
)
RH= 2.18 x 10-18 J, planck’s constant h = 6.63 x 10-34 (J•s)
CHEM 1411 EXAM 2
NAME:______________
1. As the frequency of an electromagnetic wave increases
A) its speed must increase.
C) its amplitude must increase.
B) its wavelength must increase.
D) its energy must increase.
2. Calculate the frequency of visible light having a wavelength of 686 nm.
A) 4.37  1014 /s
D) 2.29  10–15 /s
B) 4.37  105 /s
E) 2.29  10–6 /s
C) 6.17  1014 /s
3. What is the energy in joules of one photon of microwave radiation with a wavelength 0.122
m? (c = 2.9979  108 m/s; h = 6.626  10–34 Js)
A) 2.70  10–43 J
D) 4.07  10–10 J
B) 5.43  10–33 J
E) 2.46  109 J
–24
C) 1.63  10 J
4. Calculate the energy, in joules, required to excite a hydrogen atom by causing an electronic
transition from the n = 1 to the n = 4 principal energy level. Recall that the energy levels
of the H atom are given by
En = –2.18  10–18 J(1/n2)
A) 2.07  10–29 J
D) 3.27  10–17 J
5
B) 2.19  10 J
E) 2.25  10–18 J
C) 2.04  10–18 J
5. Calculate the wavelength of the light emitted by a hydrogen atom during a transition of its
electron from the n = 4 to the n = 1 principal energy level. Recall that for hydrogen En =
–2.18  10–18 J(1/n2)
A) 97.2 nm B) 82.6 nm C) 365 nm D) 0.612 nm E) 6.8  10–18 nm
6. The number of orbitals in a d subshell is
A) 1 B) 2 C) 3 D) 5 E) 7
7. The orbital diagram for a ground-state oxygen atom is
8. Which ground-state atom has an electron configuration described by the following orbital
diagram?
A) phosphorus
B) germanium
C) selenium
D) tellurium
E) none of these
9. The ground-state electron configuration of Cr, Mo, and Ag are exceptions to the Aufbau
principle. Which of the following is the electron configuration for Mo?
A) [Kr]5s14d5 B) [Kr]5s24d4 C) [Xe]6s25d4 D) [Ar]4s24d4 E) [Kr]5s24d6
10. Which of the following is the electron configuration of a ground state of an iron Fe3+ atom?
A) [Ar]4s23d7 B) [Ar]4s23d6 C) [Ar]4s23d8 D) [Ar]4s13d6 E) [Ar] 3d5
11. How many electrons are there in the 2nd principal energy level (n = 2) of a phosphorus
atom?
A) 3 B) 5 C) 6 D) 8 E) 10
12. Which one of the following sets of quantum numbers is not possible?
13. A ground-state atom of manganese has ___ unpaired electrons and is _____.
A) 0, diamagnetic
D) 5, paramagnetic
B) 2, diamagnetic
E) 7, paramagnetic
C) 3, paramagnetic
14. Which of the following processes is endothermic?
A) O2(g) + 2H2(g)  2H2O(g)
B) H2O(g)  H2O(l)
C) 3O2(g) + 2CH3OH(g)  2CO2(g) + 2H2O(g)
D) H2O(s)  H2O(l)
15. Copper metal has a specific heat of 0.385 J/g·°C. Calculate the amount of heat required to
raise the temperature of 22.8 g of Cu from 20.0°C to 875°C.
A) 1.97  10–5 J B) 1.0  10–2 J C) 329 J D) 7.51 kJ E) 10.5 kJ
16. Calculate the amount of heat necessary to raise the temperature of 12.0 g of water from
15.4°C to 93.0°C. The specific heat of water = 4.18 J/g·°C.
A) 0.027 J B) 324 J C) 389 J D) 931 J E) 3,890 J
17. When 0.7521 g of benzoic acid was burned in a calorimeter containing 1,000. g of water, a
temperature rise of 3.60°C was observed. What is the heat capacity of the bomb
calorimeter, excluding the water? The heat of combustion of benzoic acid is –26.42 kJ/g.
A) 15.87 kJ/°C
D) 1.34 kJ/°C
B) 4.18 kJ/°C
E) 752.1 kJ/°C
C) 5.52 kJ/°C
18. Octane (C8H18) undergoes combustion according to the following thermochemical equation:
2C8H18(l) + 25O2(g)  16CO2(g) + 18H2O(l)
H°rxn = –11,020 kJ/mol.
Given that H°f[CO2(g)] = –393.5 kJ/mol and H°f[H2O(l)] = –285.8 kJ/mol, calculate
the standard enthalpy of formation of octane.
A) –210 kJ/mol
D) –420 kJ/mol
B) –11,230 kJ/mol
E) 420 kJ/mol
C) 22,040 kJ/mol
19. Calculate the standard enthalpy of formation of liquid methanol, CH3OH(l), using the
following information:
C(graph) + O2  CO2(g)
H° = –393.5 kJ/mol
H2(g) + (1/2)O2  H2O(l)
H° = –285.8 kJ/mol
CH3OH(l) + (3/2)O2(g)  CO2(g) + 2H2O(l)
H° = –726.4 kJ/mol
A)
B)
C)
–1,691.5 kJ/mol
–238.7 kJ/mol
1691.5 kJ/mol
D)
E)
47.1 kJ/mol
–47.1 kJ/mol
20. Calculate the standard enthalpy change for the reaction
2C8H18(l) + 17O2(g)  16CO(g) + 18H2O(l).
Given:
2C8H18(l) + 25O2(g) 16CO2(g) + 18H2O(l) H° = –11,020 kJ/mol
2CO(g) + O2(g)  2CO2(g)
H° = –566.0 kJ/mol
A) 10,450 kJ/mol
D) –6,492 kJ/mol
B) 6,492 kJ/mol
E) –10.450 kJ/mol
C) 15,550 kJ/mol
21. For the reaction
C(graphite) + O2(g)  CO2(g)
H° = –393 kJ/mol
how many grams of C(graphite) must be burned to release 275 kJ of heat?
A) 22.3 g B) 0.70 g C) 12.0 g D) 17.1 g E) 8.40 g
22. Ethanol (C2H5OH) burns according to the equation
C2H5OH(l) + 3O2(g)  2CO2(g) + 3H2O(l), H°rxn = –1367 kJ/mol.
How much heat is released when 35.0 g of ethanol is burned?
A) 1,797 kJ B) 1,367 kJ C) 9.61  10–4 kJ D) 4.78  104 kJ E) 1,040 kJ
23. A sample of nitrogen gas has a volume of 32.4 L at 20°C. The gas is heated to 220ºC at
constant pressure. What is the final volume of nitrogen?
A) 2.94 L B) 19.3 L C) 31.4 L D) 54.5 L E) 356 L
24. If the pressure on a gas sample is tripled and the absolute temperature is quadrupled, by what
factor will the volume of the sample change?
A) 12 B) 4/3 C) 3/4 D) 1/3 E) 4
25. A gas evolved during the fermentation of sugar was collected. After purification its volume
was found to be 25.0 L at 22.5°C and 702 mmHg. How many moles of gas were
collected?
A) 0.95 mol B) 1.05 mol C) 12.5 mol D) 22.4 mol E) 724 mol
26. How many molecules of N2 gas can be present in a 2.5 L flask at 50°C and 650 mmHg?
A) 2.1  10–23 molecules
D) 3.6  1025 molecules
22
B) 4.9  10 molecules
E) 0.081 molecules
C) 3.1  1023 molecules
27. Calculate the density of CO2(g) at 100°C and 10.0 atm pressure.
A) 1.44 g/L B) 134 g/L C) 44.0 g/L D) 53.6 g/L E) 14.4 g/L
28. What is the molar mass of Freon-11 gas if its density is 6.13 g/L at STP?
A) 0.274 g/mol B) 3.64 g/mol C) 78.2 g/mol D) 137 g/mol E) 365 g/mol
29. What volume of oxygen gas at 320 K and 680 torr will react completely with 2.50 L of NO
gas at the same temperature and pressure?
2NO(g) + O2(g)  2NO2(g)
A) 1.25 L B) 2.50 L C) 3.00 L D) 1.00 L E) 5.00 L
30. Which gas has molecules with the greatest average molecular speed at 25°C?
A) CH4 B) Kr C) N2 D) CO2 E) Ar
31. Which of the following compounds is a nonelectrolyte?
A) NaF
D) NaOH
B) HNO3
E) C6H12O6 (glucose)
C) CH3COOH (acetic acid)
32. Based on the solubility rules, which of the following will occur if solutions of CuSO4(aq) and
BaCl2(aq) are mixed?
A) CuCl2 will precipitate; Ba2+ and SO42– are spectator ions.
B) CuSO4 will precipitate; Ba2+ and Cl– are spectator ions.
C) BaSO4 will precipitate; Cu2+ and Cl– are spectator ions.
D) BaCl2 will precipitate; Cu2+ and SO42– are spectator ions.
E) No precipitate will form.
33. The oxidation number of N in NaNO3 is
A) +6 B) +5 C) +3 D) –3 E) None of the above.
34. The oxidation number of Cr in Cr2O72– is
A) –12 B) –7 C) –2 D) +6 E) +7
35. In the following redox reaction
4NH3 + 3Ca(ClO)2  2N2 + 6H2O + 3CaCl2
which element is oxidized and which is reduced?
A) H is oxidized and N is reduced
D) Cl is oxidized and O is reduced
B) N is oxidized and Cl is reduced
E) Cl is oxidized and N is reduced
C) N is oxidized and O is reduced
36. In the following chemical reaction the oxidizing agent is
5H2O2 + 2MnO4– + 6H+  2Mn2+ + 8H2O + 5O2
A) H2O2 B) MnO4– C) H+ D) Mn2+ E) O2
37. In the following chemical reaction the oxidizing agent is
5S + 6KNO3 + 2CaCO3  3K2SO4 + 2CaSO4 + CO2 + 3N2
A) S B) N2 C) KNO3 D) CaSO4 E) CaCO3
38.Predict the products of the following single replacement reaction.
Fe(s) + CuSO4(aq) 
A) Cu(s) + FeSO4(aq)
D) FeCuSO4(aq)
B) Fe(s) + Cu(s) + SO4(aq)
E) FeO(s) + CuSO3(aq)
C) CuS(s) + Fe2SO4(aq)
39. Which of the following represents a combustion reaction?
A) 2C2H6(g) + 7O2(g)  4CO2(g) + 6H2O(l)
B) LiOH(aq) + HNO3(aq)  LiNO3(aq) + H2O(l)
C) N2(g) + 3H2(g)  2NH3(g)
D) 2Na(s) + 2H2O(l)  2NaOH(aq) + H2(g)
E) 2Al(s) + 3H2SO4(aq)  Al2(SO4)3(aq) + 3H2(g)
40.What mass of K2CO3 is needed to prepare 200. mL of a solution having a potassium ion
concentration of 0.150 M?
A) 4.15 g B) 10.4 g C) 13.8 g D) 2.07 g E) 1.49 g
41.A 20.00 mL sample of 0.1015 M nitric acid is introduced into a flask, and water is added until
the volume of the solution reaches 250. mL. What is the concentration of nitric acid in
the final solution?
A) 1.27 M
D) 3.25  10–2 M
–3
B) 8.12  10 M
E) 5.08  10–4 M
C) 0.406 M