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practice test1 chem1211 1. Which of the following is a chemical change? A. carving a piece of wood B. condensing water vapor into rainfall C. boiling of water D. broiling a steak on a grill E. melting wax 2. The distance between carbon atoms in ethylene is 134 picometers. Which of the following expresses that distance in meters? A. 1.34  10-10 m B. 1.34  10-6 m C. 1.34  10-13 m D. 1.34  10-12 m E. 1.34 -7  10 m

3. The area of a 15-inch pizza is 176.7 in2. Express this area in square centimeters. (1 inch=2.54cm) A. 1140. cm2 B. 69.57 cm2 C. 448.8 cm2 D. 27.39 cm2 2 cm

E. 96.8

4. Acetone, which is used as a solvent and as a reactant in the manufacture of Plexiglas®, boils at 56.1C. What is the boiling point in degrees Fahrenheit? A. 159F B. 43.4F C. 101F D. 133F E. 69.0F

5. Select the answer that expresses the result of this calculation with the correct number of significant figures.

A. 13.4

B. 13.36

C. 13.3568

D. 13.357

E. 13

6. Which measurement is expressed to 4 significant figures? A. 1300 K B. 62.40 g C. 82,306 m D. 24.049 cm E. 0.00423 kg 7. Select the answer with the correct number of decimal places for the following sum:

A. 269.0186 cm

B. 269.02 cm C. 269.0 cm

D. 269.019 cm

E. 269.01860 cm

8. The appropriate number of significant figures in the result of 15.234 - 15.208 is A. 1 B. 5 C. 3 D. 2 E. 4 9. Bud N. Chemist must determine the density of a mineral sample. His four trials yield densities of 4.77 g/cm3, 4.67 g/cm3, 4.69 g/cm3, and 4.81 g/cm3. Independent studies found the correct density to be 4.75 g/cm3. Which of the following statements represents the best analysis of the data? A. Bud's results have low accuracy and low precision B. Bud's results have much greater precision than accuracy C. Bud's results have high accuracy and high precision D. Bud's equipment is faulty E. Bud's results have much greater accuracy than precision

10. Which of the following correctly expresses 52,030.2 m in scientific notation? A. 5.20  104 m B. 5.20302  104 m C. 5.20302  105 m D. 5.203  104 m  104 m

E. 5.2

11. Silicon, which makes up about 25% of Earth's crust by mass, is used widely in the modern electronics industry. It has three naturally occurring isotopes, 28Si, 29Si, and 30Si. Calculate the atomic mass of silicon. Isotope Isotopic Mass (amu) 28 Si 27.976927 29 28.976495 Si 30 Si 29.973770

A. 28.0855 amu B. 29.2252 amu E. 27.9801 amu

Abundance % 92.23 4.67 3.10

C. 28.7260 amu

12. Which of the following is a non-metal? A. lithium, Li, B. bromine, Br, C. mercury, Hg, E. sodium, Na, 13. Which of the following compounds is ionic? A. CS2 B. HCl C. MgCl2 D. PF3

E. SO2

D. 28.9757 amu

D. bismuth, Bi,

14. Sodium oxide combines violently with water. Which of the following gives the formula and the bonding for sodium oxide? A. NaO, ionic compound B. NaO, covalent compound C. Na2O2, ionic compound D. Na2O, ionic compound E. Na2O, covalent compound 15. The substance, CoCl2, is useful as a humidity indicator because it changes from pale blue to pink as it gains water from moist air. What is its name? A. cobalt chloride B. cobalt dichloride C. cobalt(II) chloride D. copper(II) chloride E. cobaltic chloride 16. Which one of the following combinations of names and formulas of ions is incorrect? A. NO3- nitrate B. Al3+ aluminum C. O2- oxide D. CrO42- chromate E. PO43phosphate 17. The compound, (NH4)2S, can be used in analysis for trace amounts of metals present in a sample. What is its name? A. ammonia(I) sulfite B. diammonium sulfide C. ammonium sulfite D. ammonium sulfide E. ammonium(I) sulfide 18. What is the formula for lithium nitrite? A. LiNO2 B. Li2NO2 C. LiNO3

D. Li2NO3

E. LiNO4

19. What is the name of the acid formed when HBr gas is dissolved in water? A. hydrobromidic acid B. hydrobromic acid C. hydrobromous acid acid E. bromic acid

D. bromous

20. What is the name of PCl3? A. phosphoric chloride B. phosphorus chloride C. phosphorus trichloride D. phosphorus trichlorate E. trichlorophosphide 21. Aluminum sulfate, Al2(SO4)3, is used in tanning leather, purifying water, and manufacture of antiperspirants. Calculate its molar mass. A. 450.06 g/mol B. 315.15 g/mol C. 342.15 g/mol D. 74.98 g/mol E. 278.02 g/mol

22. Magnesium fluoride is used in the ceramics and glass industry. What is the mass of 1.72 mol of magnesium fluoride? A. 92.9 g B. 43.3 g C. 107 g D. 62.3 g E. 74.5 g

23. What is the mass in grams of 0.250 mol of the common antacid calcium carbonate? A. 25.0 g B. 17.0 g C. 4.00  102 g D. 4.00  10-2 g E. 2.50  10-3 g

24. Sulfur trioxide can react with atmospheric water vapor to form sulfuric acid that falls as acid rain. Calculate the mass in grams of 3.65  1020 molecules of SO3. A. 20.6 g B. 1650 g C. 6.06  10-4 g D. 2.91  10-2 g E. 4.85  10-2 g

25. Household sugar, sucrose, has the molecular formula C12H22O11. What is the % of carbon in sucrose, by mass? A. 52.8 % B. 42.1 % C. 41.4 % D. 26.7 % E. 33.3 % 26. Hydroxylamine nitrate contains 29.17 mass % N, 4.20 mass % H, and 66.63 mass O. If its molar mass is between 94 and 98 g/mol, what is its molecular formula? A. N3H3O3 B. NH2O5 C. N2H2O4 D. N4H8O2 E. N2H4O4 27. Balance the following equation: B2O3(s) + HF(l)  BF3(g) + H2O(l) A. B2O3(s) + 3HF(l)  2BF3(g) + 3H2O(l) B. B2O3(s) + 2HF(l)  2BF3(g) + H2O(l) C. B2O3(s) + 6HF(l)  2BF3(g) + 3H2O(l) D. B2O3(s) + 6HF(l)  2BF3(g) + 6H2O(l) E. B2O3(s) + H6F6(l)  B2F6(g) + H6O3(l)...