1. Would freezing liquid mercury be considered a physical or chemical change?

2. physical

3. Would dissolving sodium chloride in water be considered a physical or chemical change?

4. physical

5. What are the two categories of pure substances?

6. Elements and compounds

7. How can an element be further separated? By ordinary physical means; By ordinary chemical means; Or it cannot be further separated by ordinary physical or chemical means.

8. Cannot be separated by ordinary physical or chemical means

9. As what type of matter would you classify vinegar?

10. Homogeneous mixture

11. At one point in the school year, our room was a comfortable 85 °F. Is this observation qualitative or quantitative?

12. quantitative

13. A group of measurements that closely agree with one another but are far from the “true” value are said to be…

14. precise

15. How many sig figs are in the following measurement: 0.0390060

16. 6 sf

17. Object A has a mass of 15.2 g and a volume of 3.6 mL. Object B has a volume of 4.1 mL and a mass of 16.8 g. Which will sink first in water?

18. Object A (4.22g/mL vs. B= 4.10g/mL

19. You are in the lab and need to mix hydrochloric acid and water. In what order should you do this?

20. Pour acid into water

21. Which subatomic particle has a mass so small that it is considered negligible when finding mass number?

22. electron

23. An unknown element has 38 protons, 36 electrons, and 50 neutrons. Identify the symbol for the element and give its charge if one is needed.

24. Sr 2+

25. Isotopes occur when atoms of the same element have different mass numbers. Therefore, an isotope has the same # of ______, but a different # of ______.

26. Same = protons Different = neutrons

27. An atom has an atomic # of 31 and a mass # of 70. How many protons, electrons, and neutrons does the atom have?

28. Protons = 31 Electrons = 31 Neutrons = 39

29. What family has an electron configuration that ends in p 5 ?

30. Halogens

31. What is the Noble Gas configuration for Tungsten?

32. [Xe]6s 1 4f 14 5d 5

33. How many electrons can be held in each energy level (n=1-4) of the atom?

34. n = 1  2e- (s) n = 2  8e- (s, p) n = 3  18e- (s, p, d) n = 4  32e- (s, p, d, f)

35. Calculate the wavelength of a photon with an energy of 1.66x10 -20 kJ.

36. J = 1.66x10 -17 J V = 2.5 x10 16 Hz Wavelength = 1.2 x10 -8 m

37. Do metals generally form cations or anions?

38. cations

39. Give the group and period trend for atomic radius.

40. Decreases across a period, increases down a column.

41. Which molecule is nonpolar: BH 3 or PH 3 ?

42. BH 3

43. According to VSEPR theory, what is the molecular geometry of the compound chlorine pentafluoride ?

44. Square pyramidal

45. What type of bond is likely to form between two atoms with the same electronegativity value?

46. A nonpolar covalent bond

47. When comparing single, double and triple covalent bonds, a single covalent bond has the ____ bond length and the _____ bond enthalpy.

48. Single Covalent Bond Longest – bond length Lowest/weakest – bond enthalpy

49. What is the correct name for Mn(CrO 4 ) 2 ?

50. Manganese (IV) chromate

51. What is the correct name for C 3 H 8 ?

52. Tricarbon octahydride

53. What is the correct formula for ammonium sulfite?

54. (NH 4 ) 2 SO 3

55. A compound contains 47.0% K, 14.5% C, and 38.5 % O. Its molecular weight is 166.22 g/mol. What is its molecular formula?

56. K2C2O4K2C2O4

57. If aqueous solutions of strontium chloride and sodium sulfate are mixed together, will a precipitate form?

58. Yes, strontium sulfate is insoluble (s)

59. What do we call the ions that appear in identical forms among both the reactants and products of a complete ionic equation that are not written in the net ionic equation?

60. Spectator ions

61. Classify and balance the reaction below: __ K 3 PO 4 + __CdCl 2  __KCl + __Cd 3 (PO 4 ) 2

62. Double Replacement 2 K 3 PO 4 + 3 CdCl 2  6 KCl + 1 Cd 3 (PO 4 ) 2

63. In the balanced combustion reaction of ethane (C 2 H 6 ), oxygen has the stoichiometric coefficient of ____.

64. Seven 2 C 2 H 6 + 7 O 2  4 CO 2 + 3 H 2 O

65. What is the molar mass of magnesium nitrate?

66. Mg(NO 3 ) 2 = 148.33 g/mol

67. How many moles of pyridine (C 5 H 5 N) are contained in 3.13g of pyridine?

68. 0.0396 moles

69. In an experiment, a 0.33 mole sample of N 2 reacts completely. What is the mass of Mg consumed in the reaction? 3 Mg + N 2  Mg 3 N 2

70. 24.07 g Mg

71. In an experiment, the reaction of 4.73g of Mg with 1.83g of H 2 O actually produced 0.095g of H 2. What is the percent yield of this reaction? Mg (s) + 2 H 2 O (l)  Mg(OH) 2 (s) + H 2 (g)

72. 92.23% yield

73. Write the following balanced chemical reaction: The combustion of liquid ethanol, C 2 H 6 O.

74. C 2 H 6 O (l) + 3O 2 (g)  2CO 2 (g) + 3H 2 O (g)

75. Write the following balanced chemical reaction: Aluminum chloride is heated.

76. 2 AlCl 3 (s)  2 Al (s) + 3 Cl 2 (g)

77. Write the following balanced chemical reaction: Copper metal is placed into a solution of lithium nitride.

78. No Reaction Cu is less reactive than Li (on the activity series)

79. Write the following balanced chemical reaction: Magnesium reacts with nitrogen.

80. 3 Mg (s) + N 2 (g)  Mg 3 N 2 (s)

81. Write the following balanced chemical reaction: Solutions of sodium carbonate and chromium (III) nitrate are combined

82. 3 Na 2 CO 3 (aq) + 2 Cr(NO 3 ) 3 (aq)  Cr 2 (CO 3 ) 3 (s) + 6 NaNO 3 (aq) …rxn formed a precipitate