CHEM 101 Fall 06 Exam 1
On the answer sheet (scantron) write your Name, Student ID Number, and Recitation
Section Number. Choose the best (most correct) answer for each question AND ENTER
IT ON YOUR ANSWER SHEET.
Potentially useful data:
Avogadro’s Constant: 6.022 × 1023 mol-1
The speed of light is: c = 3.00 × 108 m/s.
The Planck constant is: h = 6.626 × 10-34 J s.
The Rydberg constant is: RH = 2.179 × 10-18 J.
∆E = - RH (1/n2 – 1/m2)
En = - RH /n2
E = hc/λ
1. How many grams of magnesium (Mg) contain the same number of atoms as 20 g of
neon (Ne)?
a. 20 g
b. 24 g
c. 48 g
d. 12 g
2. Which formula name combination is incorrect?
a. N2O3 and dinitrogen trioxide
b. P4O10 and tetraphosphorus decaoxide
c. AsF5 and arsenic pentafluoride
d. SF6 and sulfur heptafluoride
3. Which of the following is not an ionic compound?
a. NaOH
b NaF
c. CO2
d. CaO
4. A combustion reaction produces 49.4 g of CO2. Determine the number of moles of
carbon dioxide present.
a. 1.78 moles
b. 1090 moles
c. 0.891 moles
d. 1.12 moles
5. In the reaction given below, how many grams of water are consumed if 4.0 g of
hydrogen gas and 32.0 g of oxygen gas are produced?
2 H2O → 2 H2 + O2
a. 2.0 g
b. 4.0 g
c. 18.0 g
d. 36.0 g
6. In the reaction given below, if 18 moles of oxygen gas are consumed, how many moles
of aluminum oxide are produced?
4 Al + 3 O2 → 2 Al2O3
a. 3
b. 6
c. 12
d. 18
7. In the reaction below, 8.0 g of H2 react with 9.0 g of O2. Which of the following
statements is true?
2 H2 + O2 → 2 H2O
a. The equation is not balanced.
b. The H2 is the limiting reactant.
c. The O2 is the limiting reactant.
d. 2.0 moles of H2O would be produced.
8. How many moles of H2O will be produced if 3.5 moles of ammonia react with 2.5
moles of oxygen?
4 NH3 + 5 O2 → 4 NO + 6 H2O
a. 2.4 mol
b. 3.0 mol
c. 5.3 mol
d. 6.0 mol
9. How many grams of HCl are required to completely react with 25.0 g of aluminum?
2 Al + 6 HCl → 2 AlCl3 + 3 H2
a. 22.6 g
b. 67.5 g
c. 102 g
d. 136 g
10. The correctly balanced equation for the reaction between iron(III) oxide and
aluminum is:
a. Al (s) + FeO2 (s) → AlO3 (s) + Fe (s)
b. 2 Al (s) + Fe2O3 (s) Æ Al2O3 (s) + 2 Fe (s)
c. Al (s) + Fe2O3 (s) Æ AlO3 (s) + Fe (s)
d. Al (s) + Fe2O3 (s) Æ Al3O2 (s) + Fe (s)
11. What species is the reducing agent in the reaction below?
Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s)
a. Zn
b. Cu2+
c. CuSO4
d. Zn2+
12. Which substance is oxidized in the reaction below?
NaNO3 + Pb → NaNO2 + PbO
a. Pb
b. PbO
c. NaNO3
d. NaNO2
13. What is the oxidation number of O in O2?
a. -1
b. +1
c. 0
d. -2
14. Which of the compounds below has chlorine in the 5+ oxidation state?
a. Al(ClO3)3
b. NaClO
c. Cl2O
d. HClO4
15. What is the wavelength of light that has a frequency of 5.45 × 1014 hertz?
a. 1.82 × 106 nm
b. 1.82 × 10-3 nm
c. 5.50 × 10-7 nm
d. 550 nm
16. Determine the energy of a photon that has a frequency of 5.23 × 1014 Hz.
a. 1.27 × 10-48 J
b. 1.16 × 10-27 J
c. 3.47 × 10-19 J
d. 7.87 × 1047 J
17. Which statement regarding the Bohr model of the atom is false?
a. When the electron in hydrogen gains a quantized amount of energy, it moves to the
ground state.
b. Electrons cannot be located between energy levels.
c. Light is emitted when an electron moves from the excited to the ground state.
d. Electrons in the lowest energy level are in the ground state.
18. Electromagnetic radiation that is low in energy consists of waves that have _______
wavelengths and _______ frequencies.
a. long, high
b. long, low
c. short, high
d. short, low
ANSWER KEY
ANS
ANS
ANS
ANS
ANS
ANS
ANS
ANS
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ANS
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1
2
3
4
5
6
7
8
9
10
B
D
C
D
D
C
C
B
C
B
ANS
ANS
ANS
ANS
ANS
ANS
ANS
ANS
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11
12
13
14
15
16
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18
A
A
C
A
D
C
A
B