1. What is the formula for the binary ionic compound of magnesium and fluorine?
A. MgF
B. Mg2F
C. MgF2
D. Mg2F3
E. Mg3F2
2. The atomic number of the element radium is 88. How many neutrons does
radium-226 have?
A. 88
B. 98
C. 116
D. 138
E. 226
3. What is the empirical formula for the ionic compound containing cobalt(III)
and dichromate ions?
A. Co2(Cr2O7)3
B. CoCr2O7
C. Co2(CrO4)3
D. CoCrO4
E. Co(CrO4)3
4. What is the empirical formula for the compound C 14H8O2?
A. C14H8O2
B. CHO
C. C7H4O2
D. C8H4O
E. C7H4O
5. Which solution of the equation x = (74.9786 - 12.867) × (0.044904 ÷ 3.5634)
shows the appropriate number of significant figures?
A. x = 0.7826961
B. x = 0.78270
C. x = 0.783
D. x = 0.78
E. x = 0.8
6. Water is an example of which of the following:
A. heterogeneous mixture
B. homogeneous mixture
C. element
D. compound
E. ion
7. 53.96 g of solid aluminum reacts completely with 479.42 g of liquid diatomic
bromine to form only solid aluminum bromide. What is the balanced chemical
equation for this reaction?
A. Al (s) + Br2 (g) → 2AlBr3 (s)
B. 2 Al (s) + 3 Br2 (l) → 2AlBr3 (s)
C. 53.96 Al (s) + 761.4 Br2 (l) → Al2Br6 (s)
D. 6 Al (s) + 2 Br (l) → 2AlBr3 (s)
E. 2 Al (s) + 3 Br (l) → 2AlBr3 (s)
8. 53.96 g of solid aluminum reacts completely with 479.42 g of liquid diatomic
bromine to form only solid aluminum bromide. What is the mass of solid
aluminum bromide formed in the reaction?
A. 54.0 g
B. 425.5 g
C. 479.4 g
D. 533.4 g
E. 587.4 g
9. Which of the following is not one of the postulates of Dalton’s atomic theory?
A. Atoms are small, indivisible particles.
B. Atoms cannot be created nor destroyed.
C. All atoms contain equal numbers of protons and neutrons.
D. All the atoms of an element are identical in mass and in other properties.
E. Atoms combine in whole number ratios.
10. Which of the following differs between the isotopes of an element?
A. Atomic number
B. Number of electrons
C. Number of protons
D. Mass number
E. The mass of the proton
Answer Sheet
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Directions
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Neatly write your responses in the spaces provided. Use a blue or black pen. Don't write in the margins.
Attach additional sheets if needed, and include the submission information on each additional sheet.
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Remember to complete the submission information on every page you turn in.
Free-Response Questions
Time Limit: You have 30 minutes to complete this section.
Scoring: 60 points total; question 1 is worth 30 points and question 2 is worth 30 points; points for each section are
indicated within the question.
You may use a calculator for these questions.
1. Describe how you would separate a mixture of water, cyclohexanol, and lead
shavings. (Water boils at 100C and cyclohexanol boils at 161C.) Classify each
mixture and the components at each step of the separation protocol as a
heterogeneous mixture, a homogeneous mixture, an element, or a compound.
(30 points)
2. The following four isotopes of iron are the only ones found in nature on earth:
Isotope
Percent Abundance
Atomic Mass
Iron-54
5.82%
53.9396
Iron-56
91.66%
55.9349
Iron-57
2.19%
56.9354
Iron-58
0.33%
57.9333
A. Write the nuclide symbol for each isotope, showing both the mass number and the atomic number.
(15 points)
B. Calculate the average atomic mass for the element iron from the data in the table. (15 points)