CHM 100 CHEMISTRY MAN & ENVIRONMENT Comprehensive SAMPLE MIDTERM EXAM

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1 CHM 100 CHEMISTRY MAN & ENVIRONMENT Comprehensive SAMPLE MIDTERM EXAM Multiple Choice: Identify the choice that best completes the statement or answers the question. 1. Determine the mass in grams of a gold sample which occupies a volume of ml? Gold has a density of 19.3 g/ml. a g b g c g d g e. 316 g 2. Elements A and Z react to form compound AZ. Compound AZ contains 40% A and 60% Z by mass. Which statement best explains the outcome when 100 g of A is mixed with 100 g of Z? a. The reaction will form 200 g of AZ. b. The reaction will form 100 g of AZ. c. After all possible AZ is formed, some Z will be left over. d. After all possible AZ is formed, some A will be left over. e. No reaction will occur since the reactants are in the wrong ratio. 3. How many protons, neutrons and electrons are in an 25 Mg +2 ion? a. 12 protons, 12 electrons, 13 neutrons b. 12 protons, 10 electrons, 12 neutrons c. 13 protons, 10 electrons, 12 neutrons d. 12 protons, 10 electrons, 13 neutrons e. 12 protons, 14 electrons, 13 neutrons 4. Isotopes of an element have the same number of but a different number of. a. neutrons, protons b. electrons, protons c. protons, neutrons d. neutrons, electrons e. protons, electrons 5. Which of these is the correct formula for aluminum oxide? a. Al 2 O 2 b. Al 2 O 3 c. AlO d. Al 3 O 2 e. AlO 2 6. What is the coefficient in front of oxygen (O2) when the equation is balanced? C 3 H 8 + O 2 CO 2 + H 2 O a. 2 b. 3 c. 4 d. 5 e. 10

2 7. Calculate the number of moles in a 25 g sample of carbon. a moles b moles c. 300 moles d moles e moles 8. When properly balanced, what are the correct coefficients for the reaction. H 2 + O 2 H 2 0? a. 1,1,1 b. 1,1/2,1 c. 1,2,1 d. 2,1,2 e. 10,5,10 9. A is an explanation of a scientific observation. a. law b. theory c. conclusion d. prediction e. epiphany 10. Determine the mass of one mole of silicon. a amu b g c. 14 amu d. 14 g e amu 11. Which is the correct SI unit for mass? a. gram b. pound c. ounce d. kilogram e. ton 12. What is the correct name of K 2 O? a. dipotassium monoxide b. dipotassium oxide c. potassium monoxide d. potassium oxygen e. potassium oxide 13. Which of these represents the SI prefix for centi (c)? a b c d e. 10 6

3 14. Nicotine has the chemical formula C 10 H 14 N 2. What is the molecular weight of nicotine? a. 26 amu b. 81 amu c. 138 amu d. 162 amu e. 366 amu 15. Mendeleev organized the elements of the periodic table: a. by increasing atomic number and similar properties. b. by increasing atomic weight and similar properties. c. by increasing number of electrons. d. by increasing number of isotopes. e. alphabetically. 16. Based on Rutherford's model of the atom, how many protons would be found in an atom with 17 electrons? a. 1 b. 7 c. 12 d. 17 e Which of these substances are compounds? I. neon III. water II. crude oil IV. sodium chloride a. I b. I and III c. II, III and IV d. III and IV e. II and IV 18. Which is the correct SI unit for length? a. meter b. feet c. mile d. kilometer e. centimeter 19. Which of these particles has a negative charge? a. proton b. neutron c. electron d. nucleus e. an atom 20. What is the correct number of atoms in one mole of neon? a. 10 b. 11 c d. 20 e. 12

4 21. What is the maximum number of electrons which can occupy the orbit n = 3? a. 2 b. 6 c. 8 d. 10 e Which of these statements is correct? a. The amount of carbon on earth is essentially constant. b. The amount of carbon on earth fluctuates with the seasons. c. The amount of carbon on earth is increasing due to plant and animal growth. d. The amount of carbon on earth is decreasing due to consumption of carbon based fuels. e. Both B and C are correct. 23. The long jump record is 8.90 m. What is the length in yards? (1 yd = m) a yards b. 293 yards c. 350 yards d yards e yards 24. What is the coefficient in front of sodium nitride when the equation is balanced? Na 3 N a. 0 b. 1 c. 2 d. 3 e. 4 Na(s) + N 2 (g) 25. Which of these elements has two valence electrons? a. Mg b. Li c. Al d. S e. Cl 26. A chocolate chip cookie is an example of what type of matter? a. element b. compound c. homogeneous mixture d. heterogeneous mixture e. a cookie is not matter 27. Which of the following is not true for 3 moles of CaCO 3? a. It contains 3 moles of O. b. It contains 3 moles of Ca. c. It contains 3 moles of C. d. It contains 9 moles of O. e. None of the above.

5 28. Determine the volume occupied by a 1.5 g sample of ethyl alcohol. The density of ethyl alcohol is g/ml. a. 1.9 ml b. 1.3 ml c ml d ml e ml 29. Which of these is the correct name for N 2 O 3? a. nitrogen trioxide b. trinitrogen dioxide c. dinitrogen trioxide d. nitrogen dioxygenide e. dinitrogenide dioxygenide 30. Metals tend to form ions with a positive charge. The most likely way to form a positively charged ion from an atom is by doing which of the following? a. gaining electron(s) b. gaining proton(s) c. losing electron(s) d. losing proton(s) e. losing neutron(s) 31. Which of these is the best definition of matter? a. The pull of gravity on an object. b. Anything that has weight and volume. c. Anything that has mass and occupies space. d. Anything that is directly proportional to weight. e. The measure of the amount of space an object occupies. 32. Determine the correct number of protons and electrons in P 3? a. 3 protons, 6 electrons b. 15 protons, 18 electrons c. 15 protons, 12 electrons d. 31 protons, 28 electrons e. 31 protons, 34 electrons 33. Which of these statements about atoms is incorrect? a. Atoms are the smallest visible amount of an element. b. Atoms are composed of protons, neutrons, and electrons. c. Atoms are the building blocks of all matter. d. Atoms are the smallest identifiable unit of an element. e. There are 90 different naturally occurring atoms. 34. Bromine is a member of what group/family? a. halogen b. noble gas c. alkali metal d. transition metal e. alkaline earth metals

6 35. Which of these is the correct chemical symbol for potassium? a. K b. Po c. P d. Pd e. Pt 36. Given that 1 in = 2.54 cm, which of the following is true? a. 1 in 2 = 2.54 cm 2 b. 1 in 2 = 5.08 cm 2 c. 1 in 2 = 6.45 cm 2 d. 1 in 2 = 1.27 cm 2 e. none of these 37. Which of these is the correct name for Ca(OH) 2? a. calcium carbonate b. calcium oxide c. calcium dihydride d. calcium oxygen hydride e. calcium hydroxide 38. Which division of science is primarily concerned with the study of the macroscopic world? a. biology b. chemistry c. physics d. geology e. astrology 39. Which of these is a nonmetal? a. Mg b. Br c. Cu d. Ge e. Li 40. If 15.0 ml of a metal has a mass of g, what is the density of the metal? a g/ml b g/ml c g/ml d g/ml e. none of these 41. Chlorine has two isotopes, 35Cl and 37Cl that have the respective percent abundance's of 75.77% and 24.23% and masses of amu and amu. Calculate the atomic weight of chlorine. a amu b amu c amu d amu e amu

7 Other 42. What is the chemical symbol for iron? a. In b. Ir c. I d. Fe e. none of the above 43. Ions are a. electrons b. charged atoms c. neutrons d. electrodes e. protons 44. How many neutrons are in the potassium 40 isotope? a. 59 b. 40 c. 21 d. 19 e. none of the above 45. The charge on the nucleus of a sodium atom is a. 0 b. 1+ c. 23+ d. 12+ e When added to a sealed flask and heated, 6.0 g of carbon and 16.0 g of oxygen react to form 22.0 g of carbon dioxide. How much carbon dioxide is formed when 12.0 g of carbon is reacted with g of oxygen? a g b g c g d g e g g of sulfur will react with 48 g of oxygen to produce 80 grams of sulfur trioxide. If 32 g of sulfur and 100 g of oxygen are placed into a sealed container and allowed to react, what is the mass of the material in the container after the reaction is completed? a. 32 g b. 80 g c. 100 g d. 132 g e. None of the above

8 48. Hexane is always composed of 84.0% carbon and 16.0% hydrogen. This illustrates the law of a. conservation of mass b. definite proportions c. multiple proportions d. avogradro s law e. all of the above 49. What is the name of the element with the symbol Ag a. gold b. mercury c. argon d. antimony e. silver 50. An element with the electronic structur 1s 2 2s 2 2p 4 is in which group of the periodic table? a. II A b. III A c. IV A d. VI A e. VIII A