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Chemistry 107. Exam 1-3 Good Luck!. Which of the following is NOT a hypothesis?. a) Einstein is the greatest physicist that has ever lived. b) The Moon is made of green cheese. c) The number of books in a backpack can effect spinal issues.
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Chemistry 107 Exam 1-3 Good Luck!
Which of the following is NOT a hypothesis? a) Einstein is the greatest physicist that has ever lived. b) The Moon is made of green cheese. c) The number of books in a backpack can effect spinal issues. d) Sugar free pop has no effect on a child with attention deficit issues.
2. Which of the following is correct for the material pictured? a) a gaseous pure substance b) a liquid pure substance c) a gaseous mixture d) a solid mixture e) none of the above
3. Which of the following has the largest density? a) a material that has a mass of 10.0 g and a volume of 2.00 L b) a material that has a mass of 5.00 g and a volume of 10.0 cm3 c) a material that sinks in ethanol but floats on water
4. When reading a graduated cylinder, read the volume at the bottom of the meniscus. • What volume of liquid is in the graduated cylinder? • 4 mL • 5 mL • 4.5 mL • 4.6 mL • 4.56 mL
5. A student measures the mass of a penny 4 times and records the following data. What can be said about the data if the actual mass of the penny is 2.4987 g? a) The data is both accurate and precise. b) The data is neither accurate nor precise. c) The data is accurate, but not precise. d) The data is not accurate, but it is precise.
6. Which of the following represents a chemical change? a) Freezing water to make ice cubes b) Dry ice evaporating at room temperature c) Toasting a piece of bread d) Dissolving sugar in hot coffee e) Crushing an aluminum can
7. Chlorine vaporizes at –34.4 C. What is this temperature in degrees Fahrenheit? a) –34.4 F b) –29.9 F c) 238.75 F d) 307.55 F e) 273.15 F
8. Which of the following would NOT be considered an intensive property describing an unknown sample? a) It is a solid at 25 °C. b) It has a density of 1.38 g/ cm3. c) It melts at 62.0 °C. d) It has a volume of 0.52 cm3. e) It is shiny.
9. Calculate the following with the correct number of significant figures. a) 2 b) 1.4 c) 2.2 d) 1.36 e) 2.23
10. Determine the mass of 2.5 cups of water if the density of water is 1.00 g/ cm3 and 1 cup = 240 mL. a) 2.5 g b) 6.0 x 102 g c) 1.0 x 10–2 g d) 2.4 x 102 g e) 1.0 x 102 g
11. How many ounces of mercury are in 1.0 cubic meters of mercury? Hint: the density of mercury is 13.55 g/cm3 and 1 ounce = 28.35g • 6.5 x 106 ounces • 4.8 x 105 ounces • 5.2 x 104 ounces • 6.5 x 104 ounces • 48 ounces
12. Which of the following is a pure substance? a) sweat b) beef stew c) coffee d) apple juice e) ice
13. Which of the following is a heterogeneous mixture? a) seawater b) chicken soup c) coffee d) hydrogen peroxide e) ice
14. Which of the following is a chemical property? a) squeezing oranges to make orange juice b) melting butter for popcorn c) separating sand from gravel d) hydrogen peroxide decomposes to water and oxygen e) ozone is a gas at room temperature
15. Which of the following is not a base unit? a) meter b) kilogram c) liter d) kelvin e) ampere
16. Which of the following is true? a) Energy is always conserved in a physical or chemical change. b) Systems with low potential energy tend to change in a direction of high potential energy spontaneously. c) Thermal energy is a form of potential energy. d) Objects with high potential energy are stable. e) Chemical potential energy is a form of kinetic energy.
17. Which of the following statements about a carbon atom is correct according to the plum-pudding atom model? a) Anything can penetrate a carbon atom. b) The carbon atom only has a positive charge. c) The volume of the atom is primarily from the positive charge. d) The carbon atom only has a negative charge.
18. How many neutrons are in 1000 atoms of Cl-37? a) 37 b) 37,000 c) 20 d) 20,000 e) cannot be determined
19. The mass spectrum of gallium, Ga, is shown below. The atomic mass of Ga is 69.7 amu. Which of the following statements is correct? a) All Ga atoms weigh 69.7 amu. b) The atomic mass of Ga is the average of 68.9 and 71.9. 68.9 amu, 60.1 % 71.9 amu, 39.9 % c) The atomic mass of Ga will be closer to 69 than 71 because there are more atoms that weigh 68.9 amu.
20. Which of the following elements will have properties most similar to Tin, Sn (at. no. 50)? a) lead, Pb (82) b) gallium, Ga (31) c) zinc, Zn (30) d) titanium, Ti (22) e) arsenic, As (33)
21. Which weighs more, a pea or a marble? a) Pea b) Marble
22. Which has more atoms, 10.0 g Mg or 10.0 g Ca? a) Magnesium b) Calcium c) Both have the same number of atoms.
23. Two samples of the same compound are compared:Sample 1: 24.22 g carbon and 32.00 g oxygen Sample 2: 36.22 g carbon and 48.00 g oxygenThis data shows which of the following: • a) The law of definite proportions • b) The law of multiple proportions • c) The law of conservation of mass • d) a and b only • e) a, b, and c
24. Which of the following statements is true about ions? • a) An ion is the result of an atom gaining a neutron. • b) A positively charged ion is larger than the parent atom because a proton was gained. • c) An ion is always smaller than the parent atom. • d) The gain or loss of an electron by an atom will result in an ion. • e) None of the above
25. Boron has two naturally occurring isotopes: B-10 with an isotopic mass of 10.013 amu B-11 with an isotopic mass of 11.009 amuCalculate the % abundance for each isotope if the average atomic mass of boron is 10.81 amu. • a) 50.0 % B-10, 50.0 % B-11 • b) 25.0 % B-10, 75.0 % B-11 • c) 19.8 % B-10, 80.2 % B-11 • d) 26.4 % B-10, 73.6 % B-11 • e) Not enough information to determine
26. Calculate the mass in grams of one mole of footballs if one football has a mass of 0.43 kg. • 430 g • 1.4 g • 2.6 x 1026 g • 7.1 x 10-23 g • 1.4 x 1027 g
27. Which of the following has the largest mass? • 10.0 g Li • 10.0 moles of Li • 100 g Na • 10.0 moles of K • 100 g Rb
28. Which of the following elements is an alkali earth metal? a) Li b) Fe c) Ca d) Ge e) Pb
29. Which scientist confirmed that most of an atom’s mass and all of its positive charge are contained in a small core called the nucleus? a) John Dalton b) Joseph Proust c) J. J. Thomson d) Ernest Rutherford e) Robert Milliakn
30. Which of the following is false? a) The mole can be used to specify Avogadro’s number of anything. b) Avogadro’s number is 6.122 x 1023 c) The mole is equal to the number of atoms in exactly 12 grams of carbon-12. d) The value of an elements molar mass in grams per mole is numerically equal to the element’s atomic mass.
31. There are two compounds of Ni and O. The green colored oxide of nickel has a Ni:O mass ratio of 3.67:1 and a Ni:O atom ratio of 1:1. The black colored oxide of nickel has a Ni:O mass ratio of 2.45:1. Which of the following is correct? a) The two compounds have different formulas. b) The two compounds have nickel ions with different charges. c) The Ni:O atom ratio of the black oxide is 2:3. d) This is an example of the Law of Multiple Proportions. e) All of the above are correct.
a) The picture was red on sunny days and blue on rainy days. b) The picture was blue on sunny days and red on rainy days. 32. A toy used to predict the weather had a picture containing CoCl2. It worked on the following reversible reaction: CoCl2 + 6 H2O CoCl2∙ 6 H2O Which of the following statements is correct?
33. Which of the following contains the largest number of molecules? a) 10.0 g CH4 b) 10.0 g C2H6 c) 10.0 g SO2 d) 10.0 g Xe
34. Which of the following contains the largest mass percent hydrogen? a) 10.0 g CH4 b) 10.0 g C2H6 c) 10.0 g H2O d) 10.0 g H2S
35. Hydrocarbons are composed of just the elements carbon and hydrogen. Which of the following compounds has all single bonds? a) naphthalene, C10H8 b) propane, C3H8 c) ethyne, C2H2 d) ethene, C2H4
36. Which of the following compounds exhibits both ionic and covalent bonding? a) SO2 b) CF4 c) NaCl d) Na2SO4 e) P4O10
37. Determine which formula/ name pair below is correct. a) P2O5, phosphorus pentoxide b) H2O, dihydrogen monoxide c) NaNO3, monosodium nitrate d) K2O, dipotassium monoxide e) Fe2O3, iron(II) oxide
38. Which sample represents the greatest number of moles? a) 44.01 g CO2 b) 1.0 moles C3H8 c) 6.022 x 1023 molecules C4H10 d) 18.02 g H2O e) All of the samples have the same number of moles.
39. Calculate the number of carbon atoms in 25.0 grams of isopropyl alcohol (C3H8O). a) 1.25 C atoms b) 15.0 C atoms c) 2.51 x 1023 C atoms d) 7.52 x 1023 C atoms e)2.07 x 10–24 C atoms
40. An unknown compound contains the following percents by mass: C: 60.86%, H: 5.83%, O: 23.16%, and N: 10.14%. Find the empirical formula. a) C6H8O2N2 b) C7H8O2N c) C6H8O2N d) C8H8O2N e) C8H8ON
41. What is the empirical formula of a compound containing C, H, and O if combustion of 3.69 g of the compound yields 5.40 g of CO2 and 2.22 g of H2O? a) CH3O b) C2H3O c) CHO d) C2H3O2 e) CH2O
42. What are the coefficients for the decomposition of nitroglycerin? a) 2,3,6,2,1 b) 2,3,6,5,1 c) 4,6,12,10,12 d) 4,3,12,10,1 e) 4,6,12,10,1 __ C3H5N3O9 __ N2 + __ CO2 + __ H2O + __ O2
43. What is the molecular mass of calcium phosphate? a) 310.18 g/mole b) 230.02 g/mole c) 324.99 g/mole d) 135.05 g/mole e) 214.18 g/mole
1 A 2 A 3 C 4 E 5 D 6 C 7 B 8 D 9 C 10 B 11 B 12 E 13 B 14 D 15 C 16 A 17 C 18 D 19 C 20 A 21 B 22 A 23 A 24 D 25 C (just for fun) 26 C 27 D 28 C 29 D 30 B The Answers
Answers Continued • 31 E • 32 B • 33 A • 34 A • 35 B • 36 D • 37 B • 38 E • 39 D • 40 B • 41 E • 42 E • 43 A