Honors Chemistry Midterm Exam
1. What is a QUALITATIVE observation?
2. What is a QUANTITATIVE observation?
3. When a scientist makes an observation, what is the best way to start generating ideas for research (circle one)?
a. using mathematics and computational thinking
b. argumentation from evidence
c. asking questions
d. communicating experimental results
4. How is a hypothesis different from an observation?
5. A hypothesis must be testable. What does it mean to be “testable”?
6. Convert 0.057 m to km
7. Convert 13 cm3 to mL
8. Convert 0.986 hours to seconds
9. Express these numbers in scientific notation:
a. 0.00004
b. 0.0025
c. 310000
10. Express these numbers in decimal notation:
a. 5.93 x 10-5
b. 3 x 104
c. 1 .5 x 103
11. What is matter?
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Honors Chemistry Midterm Exam
12. A physical property of matter is a characteristic that can be observed or measured without changing the
chemical makeup of a substance.
a. List three examples of physical properties you can observe without a measuring tool.
b. List three examples of physical properties you must measure using tools.
13. What is density?
14. Why do solids often have higher density than liquids?
15. Given a mass of 14 g and a volume of 28 mL, calculate the density.
16. What is the mass of an object with a density of 4.0 g/cm3 that displaces 3.0 cm 3 of water?
17. Find the density of a block with a length of 8.0 cm, a width of 4.0 cm, a height 2.0 cm, and a mass of 32 g. Would
this block float or sink in water?
18. Identify the following as physical (P) or chemical (C) changes:
a. An ice cube is placed in the sun. Later there is a puddle of water. Later still the puddle is gone.
b. Two chemicals are mixed together and a gas is produced.
c. A bicycle changes color as it rusts.
d. A marshmallow is cut in half.
e. A marshmallow is toasted over a campfire.
19. True (T) or False (F):
a. Evaporation is a physical change.
b. Burning wood is a physical change.
c. In a physical change, the makeup of matter is changed.
d. When ice cream melts, a chemical change occurs.
e. Acid rain damaging a marble statue is a physical change.
20. Define atomic number and atomic mass.
21. For beryllium, write its element symbol, its atomic number and its average atomic mass.
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Honors Chemistry Midterm Exam
22. How is a cation different from an anion?
23. The two subatomic particles in the nucleus of the atom are the __________ and the __________.
24. The charge on the __________ is –1, the charge on the __________ is +1, and the __________ is neutral.
25. __________ are atoms of an element that have different __________ due to a different number of __________.
26. Why are some elements, such as hydrogen, often found as diatomic molecules?
27. How do double and triple covalent bonds form?
28. What is the Law of Conservation of Matter?
29. What do we mean if we say a chemical equation is balanced?
30. Explain the meaning of these abbreviations:
a. (aq)
b. (s)
c. (l)
d. (g)
31. What is a coefficient?
32. What is a synthesis reaction?
33. What is a decomposition reaction?
34. What is a single replacement reaction?
35. What is a double replacement reaction?
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Honors Chemistry Midterm Exam
36. What is a combustion reaction?
37. Acid rain can cause environmental damage. Describe one way that acid rain has caused harm.
38. What is one source of acid rain?
39. List one control measure that has been able to reduce acid rain.
40. How does balancing a chemical equation demonstrate the Law of Conservation of Matter?
41. Consider the following equation: Al(NO3)3 + 3NaOH → Al(OH)3 + 3NaNO3
a. List the reactants
b. List the products
c. Is the equation balanced?
42. Balance the following equation: Al + O2 → Al2O3
43. Balance the following equation: KClO3 → KCl + O2
44. Balance the following equation: Al + H2SO4 → Al2(SO4)3 + H2
45. Consider the following equation: 2 Al + 3 ZnCl2 → 3 Zn + 2 AlCl3
a. What type of reaction is this?
b. Is the equation balanced?
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Honors Chemistry Midterm Exam
46. Consider the following equation: 3 H2S + 2 Fe(OH)3 (s) → Fe2S3 + 6 H2O
a. What type of reaction is this?
b. Is the equation balanced?
47. What is Avogadro’s number?
48. How many atoms are found in one mole of atoms?
49. How many molecules of water are there in 0.360 moles of water?
50. How many moles of Mg are in 1.25 x 1023 Mg atoms?
51. How many grams of carbon are found in 1 mole of carbon atoms?
52. Define molar mass.
53. The simplest ratio of the elements in a chemical formula is known as the __________ formula.
54. Percent composition is the percentage by mass of each element in a compound. The empirical formula of copper
sulfide is Cu2S. Calculate the percent composition by mass of copper in Cu2S.
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Honors Chemistry Midterm Exam
55. Determine the empirical formula of a compound containing 63.50 % silver, 8.25 % nitrogen, and the remainder
oxygen.
56. A compound is found to contain 63 % manganese, Mn, and 37 % oxygen. What is the compound’s empirical
formula?
57. Consider the following equation: 2 Mg + O2 → 2 MgO
a. How many moles of magnesium and oxygen are found on the reactant side of the equation?
b. How many moles of magnesium and oxygen are found on the product side of the equation?
58. How many atoms are in 6.2 moles of aluminum?
59. Convert 5.3 x 1025 molecules of CO2 to moles.
60. What is the molecular formula of the molecule that has an empirical formula of CH 2O and a molar mass of 120.1
g/mol?
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