CHE 105 HOUR EXAMINATION I 16 February 1995 University of Kentucky Department of Chemistry1. A demonstration was done in class in which a regular soft drink in a can sank in a beaker of water and a diet soft drink in a can floated. It was decided that this was due to the differences in density of the contents of the two cans. Density is therefore A. an intensive and physical property of matter. B. an intensive and chemical property of matter. C. an extensive and chemical property of matter. D. an extensive and physical property of matter.13 October 1995
2. A compound is A. a pure substance that cannot be separated into simpler substances by chemical means. B. a pure substance that can be decomposed chemically into simpler substances. C. a substance that can be separated into simpler substances by physical changes. D. a substance of variable composition.
3. Which names of the following elements are incorrectly matched with their symbols ? 1. Ca, carbon 3. Mn, manganese 2. P, potassium 4. Sn, tin A. 1 and 2 B. 1 and 4 C. 3 and 4 D. 2 and 3
4. Which alkaline-earth metal is in the same period as selenium ? A. Te B. Rb C. Ca D. K
5. Which of the following have the same number of significant digits ? 1. 1.0010 2. 0.0010 3. 1.001 x 10-6 4. 1.0010 X 107 A. 1 and 4 B. 2 and 3 C. 1 and 2 D. 3 and 4
6. The result of performing the following calculation, to the correct number of significant digits, is: (0.05060)(3.9778 x 105) / (82.1 + 68.5) A. 1.3365 x 102 B. 1.336 x 102 C. 1.34 x 102 D. 1.3 x 102
7. Which of the following represent the same temperature ? 1. -40oF 2. -40oC 3. 233 K 4. 40oC A. 2 and 3 only B. 1 and 2 only C. 3 and 4 only D. 1, 2 and 3 only
8. Which one of the following statements is true ? A. 10. km is the same as 100. cm. B. 100. L is the same as 1.00 x 104 mL. C. 300. mg is the same as 3.00 x 105 ug. D. A 700. g object has more mass than a 1.60 lb. object.
9. A certain solution has a density of 1.56 g/mL. What volume of the solution must one measure in order to obtain 354 g of the solution ? A. 2.27 x 102 mL B. 4.41 x 10-3 mL C. 5.52 x 102 mL D. 4.41 x 102 mL
10. The Millikan oil drop experiment A. demonstrated that most of the mass and positive charge of the atom are located in a small region called the nucleus. B. measured the charge to mass ratio of the proton. C. measured the charge of an electron. D. measured the mass of the neutron.
11. The atomic number of an atom gives 1. the number of protons in the atom. 2. the number of electrons of a neutral atom. 3. the number of neutrons in the atom. 4. the number of neutrons and protons in the atom. A. 1 and 4 B. 2 and 3 C. 1 and 2 D. 3 and 4
12. The species 60Ni contains A. 60 protons, 60 neutrons and 60 electrons. B. 32 protons, 28 neutrons and 60 electrons. C. 28 protons, 32 neutrons and 32 electrons. D. 28 protons, 32 neutrons and 28 electrons.
13. Which of the following contain the same number of electrons ? 1. 27Al3+ 2. 11B3+ 3. 40Ca2+ 4. 14N3- A. 1 and 2 B. 1 and 4 C. 2 and 3 D. 2 and 4
14. The correct formula for the compound formed by aluminum and sulfur is: A. AlS B. Al2S C. Al2S3 D. Al3S2
15. Which of the following compounds are correctly named ? 1. N2O5 dinitrogen pentoxide 2. LiNO2 lithium nitrite 3. K2SO4 dipotassium sulfite 4. P4O10 phosphorous(IV) oxide(X) A. 1 and 4 B. 2 and 3 C. 3 and 4 D. 1 and 2
16. Which one of the following formulas would correctly represent the compound iron(III) carbonate ? A. Fe3CO3 B. Fe(CO3)3 C. Fe2(CO3)3 D. [FeCO3]3
17. Which one of the following chemical equations is correctly balanced and represents the following word equation ? sodium phosphate + magnesium bromide = sodium bromide + magnesium phosphate A. NaPO4 + MgBr = NaBr + MgPO4 B. Na(PO4)3 + MgBr2 = NaBr2 + Mg(PO4)3 C. Na3PO4 + MgBr2 = Na3Br2 + MgPO4 D. 2 Na3PO4 + 3 MgBr2 = 6 NaBr + Mg3(PO4)2
18. When the following chemical equation is balanced according to established convention, the stoichiometric coefficients for water and ammonia are: Mg3N2 + H2O = Mg(OH)2 + NH3 water ammonia A. 3 2 B. 2 3 C. 4 4 D. 6 2
19. A 1.510 g sample of a compound containing carbon, hydrogen, and oxygen yields 2.882 g CO2 and 1.769 g H2O as a result of combustion analysis. What is the empirical formula of this compound ? A. CH3O B. C2H6O C. C7H2O5 D. C6H10O3
20. A compound containing carbon and hydrogen is found to have the empirical formula CH2. If the molar mass is determined to be 112.2 g, what is the correct molecular formula of the compound ? A. C8H16 B. C16H8 C. C9H4 D. C7H14
21. How many moles of sucrose, C12H22O11, are found in 6.340 x 1024 molecules of C12H22O11 ? A. 3.818 x 1048 mol B. 10.53 mol C. 3.601 x 103 mol D. 9.498 x 10-2 mol
22. What mass of oxygen is consumed when 10.8 g of ethane (C2H6) undergoes complete combustion ? A. 1.26 g B. 40.3 g C. 1.21 x 103 g D. 11.5 g
23. Nitroglycerin (C3H5N3O9, molar mass 227 g/mol) is a powerful explosive with the reaction below generating a large amount of heat and gaseous products. If 6.55 g of O2 is generated when 204 g of nitroglycerin reacts, what is the percent yield of oxygen in the reaction ? 4 C3H5N3O9 = 6 N2 + 12 CO2 + 10 H2O + O2 A. 5.69% B. 22.8% C. 75.3% D. 91.1%
24. What mass of hydrogen chloride is formed when 6.25 g of hydrogen reacts with 125 g of chlorine ? A. 129 g B. 131 g C. 228 g D. 357 g
25. 3.0 g of H2 is reacted with 32 g of O2 to form water according to the reaction 2 H2 + O2 = 2 H2O. Which one of the following statements is true ? A. 1 g of H2 remains, no O2 remains, 34 g of H2O is formed. B. All of the H2 and O2 are consumed, 35 g of H2O is formed. C. All of the H2 is consumed, 8 g of O2 remains, 27 g of H2O is formed. D. 24 g of O2 remains, no H2 remains, 27 g of H2O is formed.