1 st Semester Exam in High School Chemistry Examination in January of 2012
1. Substance A is a liquid, Substance B is a gas and Substance C is a solid. All of the substances are at the same temperature and pressure. Which of the following shows the correct relationship between the strength of the intermolecular forces in each substance? A. A > B > C B. B > A > C C. C > B > A D. C > A > B
2.A balloon is inflated with room temperature air, and is placed outside in the sun. The balloon expands due to the rise in temperature. Which of the following describes what happens to the molecules of air as the temperature rises? A. The molecules of air stop colliding with the balloon wall. B. The molecules of air increase in size. C. There are fewer interactions between the air molecules. D. The molecules of air move more quickly.
3. Condensation occurs when _____________________. A. a gas loses energy to become a liquid B. a solid gains energy to become a liquid C. a liquid gains energy to become a gas D. a gas loses energy to become a solid
4. As liquid carbon dioxide freezes, its molecules ________________. A. absorb heat energy and move farther apart B. absorb heat energy and move closer together C. release heat energy and move farther apart D. release heat energy and move closer together
5.Compared to the particles in a gas, the particles in a solid move_____________. A. at the same speed as the gas B. quicker and farther than the gas C. quicker than the gas D. slower than the gas
6. Which one of the following is a TRUE statement? A. Gas molecules move around freely. B. Liquids do not change shape easily. C. Gas molecules move more slowly as they are heated. D. Solids change shape easily.
7. Which of the following BEST describes what happens when most substances change from a solid state to a liquid state? A. The molecules slow down. B. The molecules move farther apart. C. The molecules get smaller. D. The molecules lose energy.
8. Unlike most substances, water is unusual because it ____ when it goes from the liquid to solid state. A. contracts B. melts C. expands D. diffuses
9. Which of the following is an example of a chemical change? A. filling a balloon with helium B. freezing a glass of water C. a plant collecting energy from the sun to create food D. a dog ripping a newspaper
10. What happens to the atoms of the reactants in a chemical reaction? A. They change into new atoms. B. They recombine to form the products. C. They change names. D. Some are lost to the environment.
11. When two substances react chemically, what type of products will be formed? A. Products will be very similar to the reactants. B. Products will be very different from the reactants. C. The products will vary from one reaction to another. D. Products of a chemical reaction cannot be predicted.
12. A good hypothesis _____________. A. can be tested by experiment B. can be an educated guess predicting the outcome of an experiment C. can only be formed when you know something about what is going to happen D. may be described by all of the above
13. In the late nineteenth century, Dmitri Mendeleev spent two years developing a table that could be used to predict which of the following? A. age of mineral samples B. movements of planets C. composition of stars D. properties of elements
14. Is science limited only to ideas and concepts that are testable? A. Yes, because scientists can only make theories about things that have been measured. B. Yes, because scientists cannot create new theories from nothing. C. No, because natural phenomena can be observed, but not always measured. D. No, because scientific theories change as public opinion changes.
15. Which family correctly labels the elements in Group 1 on the Periodic Table? A. transition metals B. alkali series C. lanthanide elements D. actinide series
16. Which is the BEST conclusion that can be made from the information shown on the graph below? A. Electrons in Period 3 are more difficult to remove from an atom than electrons in Period 2. B. In general, going from left to right across a period on the Periodic Table, electrons become increasingly difficult to remove from an atom. C. Period 2 atoms are larger in size than Period 3 atoms, decreasing the attraction of the valence electrons for the nucleus. D. As the number of valence electrons increases, the electron removal energy decreases.
17. Melting Point of Elements Use the data shown below to create a graph on the element’s melting point. Element Melting Point ( o C) Lithium186 Beryllium1290 Boron2200 Carbon3500 Nitrogen- 210.5 Oxygen-218.4 Fluorine-223 Neon-253 Potassium63 Magnesium649 Aluminum659 Silicon1434 Phosphorus44 Sulfur112.8 Chlorine-102 Argon-190 Students should make a bar graph of the data.
18. Explain how the melting point of a metal compares to the melting point of a nonmetal. 18. The melting point of a metal is generally higher, except for the nonmetal that is next to the metalloid.
19. Why is an atom considered electrically neutral? A. neutrons equal the number of protons B. proton forces pull on the neutrons C. electrons equal the number of protons D. electrons equal the number of neutrons
20. Which of the following statements describes isotopes of an atom? A. different chemical properties B. different numbers of protons C. different masses D. different numbers of electrons
21. Using the Periodic Table, predict which elements will have similar chemical properties or reactivity. A. cadmium, calcium and carbon B. magnesium, strontium and barium C. rubidium, yttrium and zirconium D. nitrogen, sulfur and bromine
22. Choose the correct Lewis Dot diagram for NaCl. A. B. C. D.
23. As the atomic number increases, within a group of elements, the atomic radius usually ________________. A. decreases B. remains the same as the one above it C. increases D. decreases, then increases
24.Which of the following increases as the electronegativity difference between 2 atoms increases? A. ionic nature of the bond B. covalent nature of the bond C. metallic nature of the bond D. electron sharing between the 2 atoms
25.What is the formula for potassium fluoride? A. KF B. KF 2 C. K 2 F D. K 2 F 2
26. What is the formula for the compound formed by iron (II) ions and chromate ions? A. FeCrO 4 B. Fe 2 CrO 4 C. Fe 2 (CrO4) 3 D. Fe(CrO4) 2
27. What is the formula for aluminum hydroxide? A. AlOH B. Al(OH) 3 C. A l 2 (OH) 3 D. A l 3 OH
28. What is the name of the compound: N 2 O 3 ? A. sodium dioxide B. dinitrogen oxide C. nitrous oxide D. dinitrogen trioxide
29. What is the formula for tin (IV) oxide? A. Tn 4 O 2 B. SnO C. TnO 2 D. SnO 2
30. What is the formula for barium nitrate? A. Ba(NO 3 ) 2 B. BaNO 2 C. Ba 2 NO 3 D. Ba(NO4) 2
31. What is the name of the compound AlPO 4 ? A. aluminum phosphide B. aluminum phosphate C. aluminum phosphite D. aluminum phosphoroxide
32. Which of the following is the metallic ion in scandium (II) chloride? A. Sd 2 + B. Cl 2- C. Sc 2 + D. Cl 1-
33. Using the Nutrition Facts label to the right, which of the following formulas is CORRECT for the highlighted ingredient? A. Na 2 PO 3 B. Na 3 PO 4 C. NaPO D. Na 3 (PO4) 2
34. Select the correct name for this compound. A l 2 (SO 4 ) 3 A. dialuminum trisulfate B. aluminum trisulfide C. aluminum sulfate D. sulfuric aluminate
35. Choose the correct name for the following. HClO 3 A. hydrogen chloroxide B. hydrogen trichlor C. hypochlorite D. chloric acid
36. What is the name of the compound NiSO 4 ? A. nickel (II) sulfite B. nickel (II) sulfide C. nickel (II) sulfate
37. What is the oxidation number of nitrogen in most compounds? A. -3 B. -2 C. -1 D. + 1
38. What is the oxidation number of hydrogen in HCl? A. 0 B. +1 C. + 2 D. + 3
39. Name the compound. H 2 O A. dihydrogen monoxide B. hydrogen oxide C. hydrogen oxalate D. hydrogen dioxide
40. Name the following. Li 2 S A. dilithium monosulfide B. lithium sulfide C. lithium disulfide D. sulfuric lithate
41. Which of the following is a possible compound formed from Calcium (2+) and the polyatomic ion Nitrate, NO 3 (-1)? A. Ca 2 NO 3 B. Ca 3 NO 2 C. CaNO D. Ca(NO 3 ) 2
42. Carbon tetrachloride is a solvent which is used as a refrigerant and also as a cleaning agent. Prior to the 1950s, carbon tetrachloride was manufactured by the chlorination of carbon disulfide: CS 2 + 3 Cl 2 → CCl 4 + S 2 Cl 2 but now it is mainly produced from methane: CH 4 + 4 Cl 2 → CCl 4 + 4 HCl How many grams of carbon tetrachloride can be produced from reacting 709.0 grams of Chlorine (Cl 2 ) with excess methane? A. 3.845 g B. 61.53 g C. 384.5 g D. 6153 g
43. What is the coefficient for potassium in the balanced equation? ____ Na + ____K 2 S → ____ K + ____ Na 2 S A. 2 B. 4 C. 6 D. 8
44. For the reaction HCl + NaOH > NaCl + H 2 O, which reactant is the limiting reactant given 100.0 g of sodium hydroxide and 100.0 g of hydrochloric acid? A. hydrochloric acid B. sodium hydroxide C. sodium chloride D. water
45. In the reaction A + B → C + D, if element B is in excess, then — A. A is the limiting reactant. B. B is the limiting reactant. C. C is the limiting reactant. D. both A and B are limiting reactants.
46.In the reaction 2RbNO 3 → 2RbNO 2 + O 2 how many moles of O 2 are produced when 5.0 mol of RbNO 3 decompose? A. 1.0 mol B. 2.5 mol C. 3.0 mol D. 7.5 mol
47. How many molecules are represented by 3.00 moles of oxygen, O 2 ? A. 4.98 x 10 24 B. 3.00 C. 6.32 x 10 2 1 D. 1.81 x 1
48. White phosphorous is used as an incendiary weapon and smoke tracer. It can also be used to create smoke screens to mask troop movement or hide platoon position. Robert Boyle was the first to use phosphorus to ignite sulfur tipped wooden splints, forerunners of our modern matches, in 1680. One of the ways in which it can be made involves the fusion of calcium phosphate with carbon and sand in an electric furnace. 2Ca 3 (PO 4 ) 2 + 6SiO 2 + 10C → 6CaSiO 3 + P 4 + 10CO Starting with 100.0 grams of calcium phosphate and assuming excess silicon dioxide and carbon, how many moles of phosphorous will be produced? A. 0.1612 moles B. 0.3224 moles C. 15510 moles D. 1.551 moles
49. Calcium hydroxide and hydrochloric acid react to form calcium chloride and water as shown in the chemical reaction. If the chemicals are present in exactly the correct ratios to fully use all of the ingredients, how many moles of water would be formed from 5 moles of HCl? __ Ca(OH) 2 + __ HCl → __ CaCl 2 + __ H 2 O A. 1 mole B. 2 moles C. 5 moles D. 10 moles
50. How many moles are in 75.0 grams of nitrogen gas – N 2 ? A. 3.00 moles B. 0.333 moles C. 2.68 moles D. 4.52 x 102 5 moles
51. In the reaction, 2 H 2 + O 2 → 2 H 2 O, what is the mole ratio of hydrogen to water? A. 2: 2 B. 2 : 1 C. 1 : 2 D. 4 : 4
52. Baking soda (sodium bicarbonate) is a compound commonly used in baked goods, as a deodorizer in refrigerators and as an antacid. Commercial quantities of baking soda are produced by mixing soda ash dissolved in water with carbon dioxide. Baking soda precipitates as a solid from this method: Na 2 CO 3 + CO 2 + H 2 O → 2 NaHCO 3 How many grams of soda ash would be needed to produce 1.00 kg of sodium bicarbonate? A. 396 grams B. 631 grams C. 1270 grams D. 1590 grams
53. In the reaction 2 H 2 + O 2 → 2 H 2 O, how many moles of oxygen are required to fully react with 6.0 mol of hydrogen? A. 3.0 mol B. 6.0 mol C. 12.0 mol D. 18.0 mol
54. Tell what is wrong with each of the following molecular formulas and write the correct formula. what is wrongcorrect formula SOO (sulfur dioxide) 2HO (Hydrogen peroxide-two hydrogen atoms and two oxygen atoms)
55. Determine the number of electrons and protons contained in an atom of the following elements: electronsprotons sulfur As element number 24 Hydrogen ion H + Potassium Cation
56. Write isotope symbols for atoms with the following characteristics. Contains 18 electrons and 20 neutrons 38 Ar 18 A calcium atom with a mass number of 40 40 Ca 20 An arsenic atom that contains 42 neutrons 75 As 33
57. What is the symbol and name for the element whose average atoms have a mass very close to three times the mass of an average beryllium atom? Al
58. Determine the molecular weights of the following in amu: NAMEFORMULAMOLECULAR WEIGHT in amu fluorine(F 2 )38 carbon disulfide(CS 2 )76 sulfurous acid(H 2 SO 3 )82 ethyl alcohol(C 2 H 6 O)46 ethane(C 2 H 6 )30
59. The molecular weight is determined for a gas that is known to be an oxide of nitrogen. The value obtained experimentally was 43.98 u. Which of the following is most likely to be the formula of the gas? A. NO B. N 2 O C. NO 2 D. NO 3
60. Which of the following may not be classified as matter A. Sand B. Heat C. Seawater D. Our atmosphere
61. Perform the following calculation and express the answer to the right number of significant figures A. 611 g/mL B. 6.110 x 10 2 g/mL C. 6.1 x 10 2 g/mL D. 6 x 10 2 g/mL
62. Perform the following calculation and express the answer to the right number of significant figures A. 3.10 B. 3.1073 C. 3.1 D. 3.11
63. Which of the following correctly converts 0.000001546 in scientific notation? A. 1.546 x 10 6 B. 1.546 x 10 5 C. 1.546 x 10 -5 D. 1.546 x 10 -6
64. Of the following elements, __________ has the most negative electron affinity. A. P B. Al C. Si D. Cl E. B
65. There are ____ electrons, __ protons, and ___ neutrons in an atom of Xe. A. 132, 54 B. 54, 132 C. 78, 54 D. 54, 78
66.__________-rays consist of fast-moving electrons. A. alpha B. beta C. gamma D. XE. none of the above
67. Consider the following selected postulates of Dalton's atomic theory: (i)Each element is composed of extremely small particles called atoms. (ii)Atoms are indivisible. (iii) Atoms of a given element are identical. (iv)Atoms of different elements are different and have different properties. Which of the postulates is(are) no longer valid? A. (i) and (ii) B. (ii) only C. (ii) and (iii) D. (iii) only E. (iii) and (iv)
68. Isotopes are atoms that have the same number of ___ but differing number of ___. A. protons, electrons B. neutrons, protons C. protons, neutrons D. electrons, protons E. neutrons, electrons
69. An atom of the most common isotope of gold, Au, has ___ p +, ___ n o, and ___e -. A. 197, 79, 118 B. 118, 79, 39 C. 79, 197, 197 D. 79, 118, 79
70. Of the following, the smallest and lightest subatomic particle is the ________. A. neutron B. proton C. electron D. nucleus E. alpha particle