Chemistry I Honors Midterm Practice Test Answer Key 1. Mass and volume 2. g and ml g for solids and liquids and g and L g for gases ml L 3. volume 4. 5 5. accuracy 6. 2 7. 3 8. 4 9. 1 10. We don t know for sure. It could have 1, 2 or 3 significant digits, but we treat this number as if it has 1 significant digit. 11. 480.g or 4.80 10 2 g 12. Away from everyone 13. Long pants, closed toed shoes, aprons or lab coats, safety goggles. 14. Short pants, jewelry on hands or wrists, dangling necklaces, blousy or fuzzy shirts or blouses, open toed shoes, sandals, tennis shoes with cloth uppers. 15. Precision 16. Accuracy 17. 8.49 ml, 8.50 m, or 8.51 ml 18. a) If/then or cause-and-effect form, b) testing a model, c) model must be mentioned (usually as a because statement, d) written so that it can be proven wrong (testable), e) it must be clear, and f) the if part of the statement clearly implies the independent variable and the then part of the statement clearly implies the dependent variable. 19. 106.0 C 20. family and group 21. Al: 1s 2 2s 2 2p 6 3s 2 3p 1 22. Coefficients S: 23. 1s 2s 2p 3s 3p He: 24. 1s Mg: 25. 1s 2s 2p 3s 26. sp 3 27. To determine the answer to this problem you must: a) Write the electron dot notation b) Write the sharing arrangement c) Write the Lewis dot formula d) Determine the best electron pair shape (tetrahedral) e) Determine the best modified electro pair shape (tetrahedral) f) Determine the best molecular shape (bent) g) Determine if this molecular shape has an uneven or an even arrangement of bonds (uneven) h) Determine the polarity of the bonds (the END is 0.58 and that is polar) i) Determine if this combination of the polarity of the bonds and the arrangement of those bonds results in a polar molecule (it does) 28. unreactive or stable 29. there would be 2 nuclides in the reactants (on the left side of the arrow) and a larger nuclide in the products 30. there would be 1 large nucleus the reactants and at least 2 smaller nuclides in the products
Chemistry I Honors Midterm Practice Test Answer Key - Page 2 31. 32. 33. 4 He 2 1 n 0 0 β 1 34. nucleus 35. electron cloud 36. fusion reactions 37. 1/8 th 38. Nuclear Band of Stability 140 130 120 110 100 90 p = 1.5n r e 80 b m u N70 n tro u60 e N 50 p = n 40 30 20 10 0 0 10 20 30 40 50 60 70 80 90 Proton Number Figure 10. Stable isotopes are plotted on this graph indicating a band of stability. Also on the graph are the lines for protons = neutrons (p = n) and protons = 1.5 neutrons (p = 1.5n). 39. Isotopes clearly falling outside the band would be unstable. Examples: 72 Ge has 40 neutrons and 32 protons 32 and falls on the band of stability so it would be stable. 199 W has 125 neutrons and 74 protons and falls 74 outside the band of stability so it would be unstable. 40. Gamma - 41. A sheet of paper, smoke, setam 42., He 2+, 4, 4 He 2 2 2 43. A helium nucleus of 2 protons and 2 neutrons, mass = 4, charge = +2, symbols are in #41,
Chemistry I Honors Midterm Practice Test Answer Key - Page 3 44. low penetration stopped by a few cm of air or thin sheet of paper, reduces the atomic mass number by 4, reduces the atomic number by 2. 45. High kinetic energy electrons, mass = 1/1850 th of alpha, charge = 1, symbols in last question 46. moderate penetration, most stopped by a few mm of metals like aluminum, it s the result of neutron decay and will increase the atomic number by 1 but will not change the mass number. 47. Very high frequency electromagnetic radiation, mass = 0, charge = 0, symbols in last question. 48. very highly penetrating, most stopped by a thick layer of steel or concrete, but even a few cm of dense lead doesn't stop all of it! It is electromagnetic radiation released from an excited nucleus. The atomic number and mass number do not change. 49. Any unstable nuclide (i.e. those that fall outside the band of stability) 50. All non-metals and a fixed number of atoms in the formula [Example: SiO 2 has a fixed number of atoms in the formula but the x subscript in (SiO 2 ) x indicates that (SiO 2 ) x does not have a fixed number of atoms.] 51. Made of metals and non-metals or it contains a polyatomic ion 52. Molecules or covalent network (lattice or crystal) structures 53. Lattice or crystal 54. Covalent or sharing of electrons 55. Covalent or sharing of electrons 56. Phosphate 57. Dinitrogen pentoxide 58. Technetium(VII) borate 59. Carbonic acid 60. CH 3 CO 2 61. Cl 2 O 5 62. Cl 2 O 5 for the S2012 test and S 5 Br 8 thereafter 63. HClO 4 64. Ionic or attractions due to opposite charges (these attractions are called electromagnetic attractions) 65. This is an ionic bond to it s typically brittle, has a higher melting or boiling point than molecular compounds, has a higher enthalpy of vaporization and fusion, is non-conductive for electricity unless it is dissolved in water or is molten 66. opposite charges (these attractions are called electromagnetic attractions) 67. sharing of 2 electrons 1 electron from each of the 2 atoms in the bond donate an electron (1) to the bond 68. There are sigma ( ) and pi ( ) bonds (1 sigma and 1 pi in a double bond and 1 sigma and 2 pi in a double bond). In double bonds there is one sigma bond and one pi bond; in triple bonds there is one sigma bond and two pi bonds. Sigma bonds (σ) lie directly on a line between the nuclei of 2 atoms. Pi bonds (π) are in two parts, with each part on opposite sides of the sigma bond. 69. 0 70. the charge on the ion 71. an atom gains or looses a electrons (the atom can gain or loose one, two, three or more electrons) 72. the element name with the ending charged to -ide 73. the charge on the metal cation 74. butan-1,4-diol 75. an amide 76. 77. 78. 79. a double balloon or double mushroom head 80. spherical 81. a single balloon or single mushroom head 82. 83. zinc sulfide 84. lithium nitrate 85. ammonia
Chemistry I Honors Midterm Practice Test Answer Key - Page 4 86. potassium hydroxide 87. aluminum sulfite 88. sp 3 89., 90. 91. Synthesis 92. 93. Decomposition 94. 95. Single displacement or single replacement 96. 2Na 2 CO 3 + Pd(NO 3 ) 4 4NaNO 3 + Pd(CO 3 ) 2 97. double replacement flame 98. 2CH 3 CH 2 CH 2 CH 3 (g) + 13O 2 (g) 8CO 2 (g) + 10H 2 O(g) 99. Gas 100. Combustion 101. Models explain the behavior we observe in ways that we cannot see. Or more correctly models explain the behavior in ways that we cannot observe. Sometimes a model describes the behavior of another model, neither of which we can see but somewhere back up the chain of models there is a phenomenon or phenomena that we can see that we are trying to explain. Models explain why the behavior occurs by attempting to explain how the underlying phenomena work to cause the observed behavior. The underlying phenomenon is the part we cannot see or otherwise observe. 102.
Not Included Chemistry I Honors Midterm Practice Test Answer Key - Page 5 From left to right: Alkali metals Alkaline-earth metals 103. Transition metals Halogens Noble gases Underneath inner transition metals 104. 105. 106.
Chemistry I Honors Midterm Practice Test Answer Key - Page 6 107. 108. 109.