When answering the following questions, please show all work for full credit. 1) List the six steps of the scientific method. (1 point each)
• Purpose • Hypothesis • Materials • Procedure • Results • Conclusion
2) Describe the main differences between an element, compound, heterogeneous mixture, and homogeneous mixture. (1 point each) • elements contain only one type of atom.
• compounds contain only one type of molecule.
• homogeneous mixtures have the same composition everywhere
in the mixture.
• heterogeneous mixtures have varying composition throughout the mixture.
3) Convert the following numbers into scientific notation: (1 point each) a) 6,700 6.7 x 103
b) 0.00348 3.48 x 10-3
4) Convert the following numbers into standard notation: (1 point each) a) 4.5 x 105 450,000
b) 9.10 x 100 9.10
element that are bonded to one another.
8) Fill in the following chart. Round the atomic masses to the nearest whole number. (0.5 point per blank)
Atomic
symbol Atomicmass numberAtomic Number ofprotons Number ofneutrons Number ofelectrons
Al
27
13
13
14
13
Ca
40
20
20
20
20
Pd
106
46
46
60
46
Es
252
99
99
153
99
9) Write the electron configuration of germanium. (1 point)
[Ar] 4s23d104p2 OR 1s22s22p63s23p64s23d104p2
10) A sample of gallium has the following isotopic abundances:
Isotope Isotopic mass (amu) Isotopic abundance (%)
69Ga 68.93 60.75
71Ga 70.92 39.25
What is the average atomic mass of this sample of gallium? Note: It may not be the same as the mass given on the periodic table. (8 points)
69.71 amu
11) Compare and contrast the type of bonding that takes place in covalent vs. ionic compounds. Your answer should explain the reasons why the bonding type is different. (6 points)
• In ionic bonds, electrons are transferred from the less
electronegative atom to the more electronegative atom. Ionic compounds are primarily formed when nonmetals bond with
12) Name the following compounds. (1 point each) a) NaOH sodium hydroxide
b) CBr4 carbon tetrabromide
c) Cr3N2 chromium (II) nitride
d) SF2 sulfur difluoride
e) NH3 ammonia
f) CoSO4 cobalt (II) sulfate
13) How many grams of copper (II) carbonate are present in 4.30 x 1024 molecules? (5 points)
882 grams
14) Describe the differences between empirical, molecular, and structural formulas, giving examples of each. (6 points)
• Empirical formulas show only the ratios of each element to each other in a compound. For ethane, the empirical formula is CH3.
• Molecular formulas tell us all of the atoms of each element present in a molecule. The molecular formula of ethane is C2H6.
• Structural formulas show the positions of each of the atoms in the molecule. Any Lewis structure is a good example of a structural formula.
15) Explain why the dipole-dipole force is able to hold molecules together. (6 points)
The dipole-dipole force arises from the alignment of the positive end of a polar molecule with the negative end of another. Because
opposite charges attract one another, the molecules are weakly held together.
Shape: trigonal bipyramidal
Bond angle: 107.50
18) Balance the following equations and indicate the type of reaction that’s taking place: (1.5 point each)
3 Ca(OH)2 + 1 Fe2(CO3)3Æ2 Fe(OH)3 + 3 CaCO3
Type of reaction: double displacement
2 NaBr + 1 H2SO4Æ1 Na2SO4 + 2 HBr
Type of reaction: double displacement
1 C3H6O + 4 O2Æ3 CO2 + 3 H2O
Type of reaction: combustion
3 Fe + 1 Cr(NO3)6Æ1 Cr + 3 Fe(NO3)2
Type of reaction: single displacement
1 NiSO3 + 1 MgF2Æ1 MgSO3 + 1 NiF2
Type of reaction: double displacement
1 P4 + 6 F2Æ1 PF3
Type of reaction: synthesis
2 H3PO4 + 3 Be(OH)2Æ6 H2O + 1 Be3(PO4)2
Answer the following questions for the reaction:
1 H
2SO
4(l)+ 2 NaCN
(s)ÆÆÆÆ 2 HCN
(g)+ 1 Na
2SO
4(s)19) How many grams of sodium cyanide would be required to make 55 grams of sodium sulfate? (4 points)
38 grams
20) If 35 grams of sulfuric acid were to react with 45 grams of sodium cyanide, how many grams of sodium sulfate would be formed? (8 points)
51 grams (sulfuric acid is the limiting reagent)
21) If the reaction in problem 20 resulted in the formation of 25 grams of sodium sulfate, what would be the percent yield of this reaction? (3 points)
49%
22) If 25 grams of sodium sulfate was formed in this reaction, how many liters of hydrogen cyanide would be formed at standard temperature and
pressure? (4 points)
7.9 L
Semester Exam Grading Scale 171 = A+
153 – 170 = A 145 – 152 = B+
137 – 144 = B 128 – 136 = C+
Mr. Guch is a man of many interests. Depending on what day you catch him, he might be wrestling alligators, chasing squirrels, or swimming with the fishes. He’s been known to sky-dive, build forged antique furniture, and go over Niagara Falls in a barrel of his own design. He’s a master chef, a licensed masseur, and able to fix fourteen brands of photocopy machine. Though shaken by the death of Jerry Garcia, Mr. Guch is now an avid supporter of the Insane Clown Posse, taking off for weeks at a time to follow their tour. Mr. Guch is currently hard at work on his fourth book, a series of articles and stories about Bootsy Collins tentatively titled Bootsy: A Profile in Greatness.
A History of the Type
The text of this book is set in Humidor Britannica, a typeface based on the 1753 Humidor Botswana font which was used in the first deck of risque playing cards. Since that groundbreaking work, Mr. Botswana has been seen jet-setting around the playgrounds of the rich and famous, both in the United States and abroad. Mr. Botswana is currently working on his long-anticipated second work, a game of internet solitaire involving risque playing cards.