Regents & Honors Chemistry
Midterm Review Worksheet
Name________________
Bring calculator, pencils, and this completed worksheet to the midterm exam.
For problems involving an equation, carry out the following steps: 1. Write the equation.
2. Substitute numbers and units. 3. Show the final answer with units. There is no credit without showing work.
Introduction (Chapters 1 & 2)
1. a. What is the difference between a physical property and a chemical property?
b. Give an example of each for H2O.
2. Is each of the following a physical (P) or chemical (C) change?
a. ice melting
b. food spoiling
c. iron rusting
d. chopping wood
3. a. What is distillation?
b. What is filtration?
c. What do these two processes have in common?
4. Draw a concept map showing the classifications of matter. Give an example of each.
5. How much carbon dioxide is formed if 6.0 g of carbon reacts exactly with 16.0 g of oxygen?
6. Classify each as element (E), compound (C), homogeneous mixture (HOM), or heterogeneous mixture
(HET):
a. air
d. nitrogen
b. gasoline
e. cement
c. ice
f. fog
Handling Numbers (Chapters 3 & 4)
7. a. What is the number 657,000 in proper scientific notation?
b. What is the number 4.98 x 10-4 in decimal notation?
8. Round each measurement to three significant figures:
a. 87.073 m
b. 0.000345001 L
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Regents & Honors Chemistry
Midterm Review Worksheet
9. Solve the following and express the result in proper scientific notation and with the correct number of
significant figures:
a. 7.18 + 5.384 =
b. (6.3 x 10-3) x (2.156 x 104) =
10. Calculate the percent error if a student measures the density of gold to be 17.2 g/cm3. Use Table S to find
the accepted value for the density of gold is 19.3 g/cm3.
11. Do the following conversions:
a. How many liters are 34 mL?
b. How many grams are 65 mg?
c. How many mm are 3.0 km?
d. How many K is 340oC?
12. Would a plastic ball with a mass of 35 g and a volume of 42 cm3 sink or float in water?
13. Convert 65 mph (miles per hour) to m/s. (1609m = 1mi).
Compounds (Chapter 6)
14. a. What is the difference between an ion and an atom of the same element?
b. What is a cation and what is an anion?
c. How many protons and electrons does the aluminum ion have?
15. a. What is the basic unit of a molecular compound called?
b. What is the basic unit of an ionic compound called?
16. What are several general differences in physical properties between molecular and ionic compounds?
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Regents & Honors Chemistry
Midterm Review Worksheet
17. Write the symbol for the ions of the following elements showing the correct charges:
a. aluminum
d. oxygen
b. sodium
e. iron
c. neon
f. lead
18. Name the following ions and/or compounds:
a. NH4+
d. Fe+2
b. N2O5
e. CuO
c. K2CrO4
f. H2CO3
19. Write the formula for the following compounds. State whether each is ionic (I) or molecular (M).
a. magnesium hydrogen carbonate
b. sulfur trioxide
c. nitric acid
d. calcium sulfide
e. ammonium phosphate
f.
iron(III) carbonate
Atoms, Electrons, and Periodic Relationships (Chapters 5, 13, & 14)
20. What did Rutherford conclude from his gold foil experiment?
21. a. Fill in the table concerning the three subatomic particles that make up an atom.
Symbol
Charge
Mass (amu)
Location in the atom
22. How many protons, neutrons and electrons are in the following atoms:
Protons
Neutrons
Electrons
Ne-20
Fe-55
2
H
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23. a. Define:
a. mass number
b. atomic number
c. atomic mass
24. What is the mass number and atomic number of Fe-55?
25. What is the isotope notation of the element that has a mass number of 47 and 25 neutrons?
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Regents & Honors Chemistry
Midterm Review Worksheet
26. Rubidium has two naturally occurring isotopes. One isotope has an abundance of 72.2% and its mass is
84.9 amu. The other isotope has an abundance of 27.8% and its mass is 87.0 amu. Determine the atomic
mass of rubidium.
27. State the key features (focus especially on the electrons), and draw a diagram showing a model of the atom
according to:
Dalton
Bohr
Quantum Mechanics
28. Describe, in detail, how the emission spectrum of neon in a neon light works.
29. Define:
a. Orbital
b. Ground state
c. Excited state
30. Give the Regents chart electron configuration and the number of valence electrons in:
Regents e- Config.
No. Valence eCarbon atom
Magnesium atom
Iron atom
Chloride ion
31. Define:
a. electronegativity
b. ionization energy
32. State the trends (increases (I) or decreases (D)) and give a brief explanation for the following properties:
a. top to bottom in Group 2: the atomic radius
b. left to right in Period 2: the atomic radius
c. top to bottom in Group 16: the first ionization energy
d. left to right in Period 2: first ionization energy
e. top to bottom in Group 17: electronegativity
f.
top to bottom in Group 14: metallic character
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Regents & Honors Chemistry
Midterm Review Worksheet
33. Which elements (general name) on the Periodic Table are usually found in salts that form colored aqueous
solutions?
34. As a metal atom forms a cation, does the size increase, decrease, or remain the same? Why?
35. As a nonmetal atom forms an anion, does the size increase, decrease, or remain the same? Why?
Ionic, Covalent, and Metallic Bonding (Chapters 15 & 16)
36. Define “ionic bond”.
37. Why do metals tend to form cations and nonmetals tend to form anions?
38. Which pair of elements are likely to form ionic compounds (I) or molecular(M) compounds?
a. chlorine and bromine
b. lithium and chlorine
c. potassium and helium
d. iodine and sodium
39. Explain why ionic compounds are electrically neutral.
40. Explain why molten MgCl2 and MgCl2(aq) conduct an electric current although crystalline MgCl2 does not.
41. Define “metallic bond”.
42. Explain why metals are good conductors of electricity.
43. What is an “alloy”?
44. Explain why neon is monatomic but chlorine is diatomic.
45. Draw the electron dot structure for:
a. I2
b. NH3
c. CH4
d. H2O
46. How many electrons are shared between two atoms in a double covalent bond? How many in a triple
covalent bond?
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Regents & Honors Chemistry
Midterm Review Worksheet
47. Draw the electron dot formula for:
a. HCN
b. CO2
48. Use VESPR theory to predict the shapes of the following species:
a. CO2
b. SO3
c. CH4
d. NH3
49. Not every molecule with polar bonds is polar. Explain this statement. Use CCl4 as an example.
50. The bonds between the following pairs of elements are covalent. Arrange them in order of increasing
polarity.
a. H-Cl
b. H-F
c. H-H
d. H-C
e. H-O
f. S-Cl
51. Draw the electron dot structure for each molecule. Identify polar covalent bonds by assigning slightly
positive (+) and slightly negative (-) symbols to the appropriate atoms.
a. BrCl
b. HBr
c. H2O
52. Which of these molecules would you expect to be polar? (Hint: use VSEPR to determine the molecular
shape whether the molecule is symmetrical.)
a. SO2
b. H2S
c. CO2
d. BF3
Chemical Reactions (Chapter 8)
53. What are the five classes of chemical reactions? For each type of reaction, what do you look for to tell
which class of reaction it is?
1.
2.
3.
4.
5.
54. a. Which Regents table is used to predict whether a single replacement reaction takes place?
b. What is meant by “calcium is more active than lead”?
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Regents & Honors Chemistry
Midterm Review Worksheet
55. a. What are the three conditions that “drive” double replacement reactions?
b. When do you use Regents Table F?
56. For each of the following reactions, (1) name the class of the reaction, and (2) predict the products and
write a balance chemical equation including states:
a. Aqueous solutions of calcium bromide and sodium carbonate are mixed.
b. Aluminum reacts with chlorine to form aluminum chloride.
c. Complete combustion of butane (C4H10).
d. Fluorine gas is bubbled through an aqueous solution of sodium chloride.
e. Magnesium carbonate is heated, yielding magnesium oxide and carbon dioxide.
f.
Zinc metal and an aqueous solution of sodium phosphate are mixed.
57. Write net ionic equations for 56a and list the spectator ions.
The Mole & Stoichiometry (Chapters 7 & 9)
58. Do the following conversions:
a. How many molecules in 2.35 mol SO3?
b. How many atoms in 2.35 mol SO3?
c. How many moles are 6.75 x 1022 formula units of calcium carbonate?
d. How many grams are 6.4 mol H2O?
e. How many liters are 3.6 mol CO2 at STP?
f.
How many atoms are in 35 L He at STP?
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Regents & Honors Chemistry
Midterm Review Worksheet
59. Write the formula for sodium carbonate. What is the percent composition of each element in sodium
carbonate?
60. What is the molecular formula for a compound with an empirical formula of C3H5O2 and a molar mass of
146 g/mol?
61. If a molecular compound is 25.9% N and 74.1% O, what is its empirical formula?
62. (Honors only) What is the molar mass of a gas with a density of 2.57 g/L?
63. For the reaction: 3NO2(g) + H2O(l)  2HNO3(aq) + NO(g):
a. How many mol NO can be formed from 0.23 mol NO2?
b. How many liters (at STP) of NO can be formed from 6.2 mol H2O?
c. How many molecules of NO can be formed from 16 g NO2?
d. How many grams of HNO3 can be formed from 75 g NO2?
64. (Honors only) For the reaction in problem 63, what is the limiting reagent if 37 g NO2 reacts with 8.0 g
H2O? How much of the excess reagent remains after the reaction?
65. (Honors only) What is the percent yield in problem 64 if 6.2 g NO is actually produced?
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