Name:
Per:
Date:
Unit 1. Materials: Formulating Matter
C. Minerals and Moles. What is the role of chemistry in the life cycle of
metals?
C.1 Metal Resources, Production, and Use
The resources for all human activities must be obtained from Earth’s atmosphere, hydrosphere, and
outer layer of its lithosphere. These resources are not uniformly distributed.
Textbook p112-115
1. List two resources typically found in each of the three major “spheres” of Earth.
2. a. List and briefly describe three major parts of the lithosphere.
b. Which layer serves as the main storehouse of chemical resources used in manufacturing consumer
products?
3. Using the table “Production of Selected Metals Worldwide, 2008, identify the nation that produces the most
a. silver
b. copper
c. tin
4. Compare the “Production of Selected Metals Worldwide, 2008” table in this packet with the one in the
textbook, which dates from about the year 2000. What major differences do you notice?
5. According to information in the table, which of these four nations—the United States, Australia, China, or
Peru—produces the largest masses of the eight listed resources in the table?
6. What are the implications if a country’s available natural resources do not match that country’s consumption
of the natural resource?
7. What factors determine the feasibility of mining a particular metallic ore at a certain site?
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Production of Selected Metals Worldwide, 2008
8. A 19th-century gold mine, inactive for over 100 years, has recently reopened for further mining. What factors
may have influenced the decision to reopen the mine?
9. What is meant by the quantity of “useful ore” at a particular site?
10. Why are active metals more difficult to process and refine than are less active metals?
11. Why do most metals exist in nature as minerals rather than as pure metallic elements?
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C.4 Composition of Materials
In 1982, due to an increase in the price of copper, the cost of making a penny exceeded
$0.01. A post-1982 penny with a mass of 2.5000 g is composed of 2.4375 g zinc and
0.0625 g copper. The percent composition of the penny can be found by dividing the
mass of each constituent metal by the mass of the penny and multiplying by 100%:
2.4375g zinc
100% 97.50%zinc
2.500g total
0.0625
g copper
100% 2.50%copper
2.500g total
Cu,
2.50
%
Zn,
97.50
%
12. A Roosevelt dime, the U.S. 10-cent coin since 1946, has a mass of 2.268 g. It is composed of 8.33% nickel
and 91.67% copper. Calculate the mass of each metal present.
13. The bodies of elite distance runners are often composed of far less body fat than the average U.S. citizen.
Calculate:
a. The percent body fat of a 58-kg female distance runner with 9.1 kg of body fat.
b. The lean body mass (the part of the body that is not fat) of a 67-kg male marathoner with 4.8% body fat.
14. Strict guidelines apply to the labeling of coffee produced from Hawaii-grown coffee beans. Consider a
coffee labeled as follows:
a. What mass, in g, of coffee beans from Kauai would
50% MOLOKAI COFFEE ALL HAWAIIAN
be contained in 1 lb (454 g) of this coffee?
Additional: 25% Kauai, 15% Kona, 10% Maui Coffee
b. What mass of Kona coffee beans would be contained in 62 kg of Molokai coffee?
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Unit Conversions – The Method
Write equivalence formulas and ratios for each of the examples below. Use the first one as a model.
=
=
Tablespoon
(Tbs)
Equivalence formula
Conversion Factors
1 gallon = 4 qt
1 gal
4 qt
=1=
4 qt
1 gal
pts
=
1” = 2.54 cm
teaspoons
(tsp)
Tablespoon
(Tbs)
teaspoons
(tsp)
How many quarts are in 2.5 gallons? Use the following steps to convert from one unit to another.
a. Start with the known quantity, 2.5 gal. Translate the word problem to an equation: 2.5 gal = ? qt
b. Set up the conversion factor units. You must get rid of the starting units, and end up with the new
units.
qt
= ? qt
gal
denominator
2.5 gal 
so the conversion factor you need has qt in the numerator, gal in
c. Fill in the correct conversion factor quantities for the problem. Plug and chug (do the math).
4 qt
2.5 gal 
= 10 qt
gal
Units cancel like other algebraic quantities. Notice that units cancel just like numbers in algebra. For
example, to solve the math problem:
3
1
=
= 1.5
2
2 4
1
Multiplying by 1/number is the same as dividing: 6  = 6  2 = 3
2
34
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Unit Conversion Practice
Solve these problems stepwise:
a. Translate the word problem to an equation
b. Set up the conversion factor units
c. Fill in the conversion factor quantities. Plug and chug
SHOW YOUR WORK, WITH CONVERSION FACTORS!
16. There are 4 cups in 1 quart. A recipe for brownies calls for 5 cups of milk. How many quarts of milk is
this?
4
=
17. One gallon equals 3.8 L. A student group buys 40 L of soda for a fundraiser. How many gallons of
soda is this?
1 gallon = 3.8 L
18. A baker is making a chocolate cake. The recipe calls for 10 tablespoons of chocolate sauce. How many
teaspoons of chocolate sauce is this equal to?
tablespoon
=
teaspoons
(tsp)
19. A recipe calls for 2 tablespons cinnamon. You are cooking for a big crowd and you need to make four
times the recipe (8 Tbs cinnamon). How many cups of cinnamon is this?
= 16
1 c = 16 Tbs
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Convert the following
20. 2.5 cups = ? tablespoons
21. 24 tablespoons = ? cups
22. 36 teaspoons = ? tablespoons
23. 24 inches = ? cm
24. 83 cm = ? inches
25. 50 inches = ? feet
26. 5.2 feet = ? inches
27. 17 gal = ? liters
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Counting by Weighing
SHOW YOUR WORK. EXPRESS NUMBERS AS DECIMALS, NOT FRACTIONS.
28. USDA large eggs weigh 68 g, on average. One dozen eggs weigh 816 g.
a. Write an equivalence formula for the mass of a dozen eggs.
b. If you have 2 dozen eggs, how much do they weigh?
c. If you have 2.5 dozen eggs, how much do they weigh?
d. If you have 0.5 dozen eggs, how much do they weigh?
e. If you have 204 g eggs, how many dozen do you have?
f.
If you have 3264 g eggs, how many dozen do you have?
29. One post-1982 penny weight 2.5 g. One dozen pennies weigh 30 g.
a. Write an equivalence formula for the mass of a dozen pennies.
b. If you have 8 dozen pennies, how much do they weigh?
c. If you have 3.2 dozen pennies, how much do they weigh?
d. If you have 15 g pennies, how many dozen do you have?
e. If you have 225 g pennies, how many dozen do you have?
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30. A 1-¾” nail weighs 2.0 g. A dozen nails weigh 24.0 g.
a. Write an equivalence factor.
b. If you have 240 g of nails, how many dozen nails do you have?
c. If you have 8.5dozen nails, how much do they weigh?
31. One mole of sulfur weighs 32 g.
a. Write an equivalence factor.
b. If you have 4 moles S, how much does it weigh?
c. If you have 4.5 moles S, how much does it weigh?
d. If you have 0.25 moles S, how much does it weigh?
e. If you have 208 g sulfur, how many moles do you have?
f.
If you have 6.4 g sulfur, how many moles do you have?
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C. 6 Introduction to the Mole Concept
The mole concept permits us literally to “count by weighing”. One mole of substance contains 6.0  1023
particles.
In the world around you, a variety of different measures are used to specify amounts. For example, at the store
you might buy 10 apples or a 5 lb bag of apples. One measure is a counting unit and the other is a unit of
weight. To compare the prices, you would probably want to know how many apples are in the 5 lb bag.
Likewise, chemists use both number and mass to specify the amount of a substance. The mole, abbreviated mol,
is a counting unit used to count a large number of atoms. A mole of atoms is equal to 600 sextillion, or 6.0 
1023 atoms. This number is also referred to as Avogadro’s number.
The following table compares the average mass of one atom with the mass of 1 mol of atoms.
Comparing Atoms and Moles
Element
Hydrogen, H
Carbon, C
Iron, Fe
Arsenic, As
Mercury, Hg
Average mass of one
atom (amu)
1.00 amu
12.01 amu
55.85 amu
74.92 amu
200.59 amu
Mass of one mole of
atoms (g)
1.00 g
12.01 g
55.85 g
74.92 g
200.59 g
The mass of one mole of atoms of an element is called the molar mass. You can find the molar mass of an
element by looking up the average atomic mass on the periodic table
28. Give the molar mass for the elements listed.
a. nitrogen, N
c. chlorine, Cl
b. neon, Ne
d. copper, Cu
29. Which has more mass?
a. 1 mol of hydrogen, H, or 1 mol of carbon, C
Ans: 1 mol H ´ 1 g H = 1 g H ; 1 mol C ´ 12 g C = 12 g C; so the mol of C has more mass
1 mol H
1 mol C
b. 1 mol of aluminum, Al, or 1 mol of gold, Au
c. 1 mol of copper, Cu, or 1 mol of gold, Au
d. 5 mol of carbon, C, or 1 mol of gold, Au
e. 1 mol iron, Fe, or 2 mol of sodium, Na
f. 2 mol of aluminum, Al, or 1 mol of nickel, Ni
g. 2 mol of platinum, Pt, or 10 mol of calcium, Ca
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30. Which contains more moles?
a. 12 g of hydrogen, H, or 12 g of carbon, C
1 mol H
1 mol C
= 12 mol H;12 g C ´
=1 mol C so the 12 g H contains more moles, and hence
1g H
12 g C
more atoms.
12 g H ´
b. 27 g of aluminum, Al, or 27 g of iron, Fe
c. 40 g of calcium, Ca, or 40 g of sodium, Na
d. 10g lithium, Li, or 100 g of lead, Pb
C.7 Molar Masses
Draw a molecular-level model and find the molar mass of each substance:
31. Carbon dioxide: CO2
O
C
O
The chemical formula and drawing show that one mole of carbon dioxide molecules contains one mole of
carbon atoms and two moles of oxygen atoms. To find the molar mass of a compound, multiply the number
of atoms of each element by the molar mass of each element. Then add the masses of the various elements.
1 C = 1  12 g/mol = 12 g/mol
2 O = 2  16 g/mol = 32
CO2
44 g/mol
32. Nitrogen gas: N2
33. Methane: CH4
34. Magnesium hydroxide, Mg(OH)2
35. Calcium nitrate, Ca(NO3)2
Unit 2.C Minerals and Moles
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36. A mole of atoms or molecules is usually an amount that you can hold in your hand if the substance is liquid
or solid. Complete this table using a periodic table for reference.
Chemical formula
Molar mass (g/mol)
Moles of what?
O2(g)
1 mol oxygen gas
O3 g)
1 mol ozone atoms
H2O()
1 mol water molecules
NaCl(s)
1 mol sodium chloride units
H2SO4(aq)
1 mol sulfuric acid
molecules
C2H6O()
1 mol ethanol molecules
C.8 Moles and Percent Composition
Example: What is the percent by mass composition of iron(III) hydroxide, Fe(OH)3?
Step 1: Find the molar mass of the compound.
1 mole Fe = 1 mol  56 g/mol
= 56 g
3 mole O = 3 mol  16 g/mol
= 48 g
3 mole H = 3 mol  1 g/mol
=
1 mole Fe(OH)3
= 107 g
3g
H
3%
O
45
%
Fe
52
%
Step 2: Find the percentage of each element:
% Fe =
56gFe
´ 100% = 52% Fe in Fe(OH)3
107g Fe(OH)3
48gO
´ 100% = 45% O in Fe(OH) 3
107gFe(OH)3
3g H
%H =
´ 100% = 3% H in Fe(OH)3
107g Fe(OH)3
%O =
100%
37. What percent of magnesium bromide, MgBr2, is magnesium?
38. What percent is zinc of Zn3(PO4)2?
Unit 2.C Minerals and Moles
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39. For each of the following food additives, calculate the weight percent sodium
a. NaCl (table salt)
b. Na3PO4 (sodium phosphate)
40. Two common iron-containing minerals are hematite (Fe2O3) and magnetite (Fe3O4). If you had the
same mass of each, which sample would contain the larger mass of iron? Support your answer with
calculations.
Fe = 56 g/mol, O = 16 g/mol.
41. You own two copper mines in different parts of the world. Your mine in Mexico is rich in the mineral
chalcopyrite (CuFeS2), while your mine in Russia is rich in the mineral malachite (Cu2CO3). Which
mine will give you the most copper per ton of mineral? Show your work. Cu = 64 g/mol, Fe = 56
g/mol, S = 32 g/mol, C = 12 g/mol, o = 16 g/mol.
42. Show the percent by mass of Cu, Fe, and S in chalcopyrite
(CuFeS2) with a pie chart.
Unit 2.C Minerals and Moles
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C.10 Mining and Refining
Knowing the percent composition of metal in a mineral and the percent composition of the mineral within an ore
provides geologists valuable information as they determine the feasibility and profitability of mining a particular
ore. However, once these ores are mined from the lithosphere, they must be refined in order to be used.
Refining in general refers to the removal of impurities from a desired material. In metallurgy, refining means to
use various methods to produce the free metal from on ore. The process of converting a combined metal ion in a
mineral to a free metal involves a particular kind of chemical change.
Formation of Copper Metal (Reduction)
In general, for metallic cations to be converted to atoms of the pure metal, each cation must gain a particular
number of electrons:
Cu2+ + 2e−  Cu
copper(II) ion
copper metal
29 protons
29 protons
27 electrons
29 electrons
LEO says GER
Loss of Electrons is Oxidation,
Gain of Electrons is Reduction
Chemists classify any chemical change in which a reactant gains one or more electrons as a reduction. Thus the
conversion of Cu2+ cations to copper metal is a reduction reaction, and we say that Cu2+ cations were reduced.
Formation of Cu2+ Ions (Oxidation)
Chemists classify the reverse reaction, in which an ion loses one or more electrons, as an oxidation:
Cu

Cu2+ + 2 e−
copper metal
copper(II) ion
29 protons
29 protons
29 electrons
27 electrons
Oxidation-Reduction Reactions
Whenever one reactant loses electrons, another reactant must simultaneously gain them. In other words,
oxidation and reduction reactions never occur separately. Oxidation and reduction occur together in what
chemists call oxidation-reduction reactions or, to use a common chemical nickname, redox reactions.
We observed the following redox reaction in the lab Relative Activity of Metals:
Cu2+(aq) + Mg(s)  Cu(s) + Mg2+(aq)
Cu2+ ions could be converted to metallic copper, Cu(s) by allowing the Cu2+ ions to react with magnesium metal,
an element more active than copper. Magnesium atoms were oxidized; Cu2+ ions were reduced.
43. Identify each of the following as either an oxidation (O) or reduction (R) reaction. If the reactant gains
electrons during the reaction, it is a reduction; if the reactant loses electrons during the reaction, it is an
oxidation.
a. Cu2+ + 2e−  Cu
Ans. During the reaction, the reactant gained electrons, so this is a reduction
b. Cl + 1e−  Cl−
c. O2−  O + 2e−
d. N + 3e−  N3−
e. Cr  Cr3+ + 3e−
Unit 2.C Minerals and Moles
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44. Write an equation for each of the following processes:
a. the reduction of gold(III), Au3+ ions, to gold metal
b. the oxidation of elemental vanadium to V4+ ions
45. Consider the following equation: Zn(s) + Ni2+(aq)  Zn2+(aq) + Ni(s)
a. Which reactant has been oxidized? Explain your choice.
b. Which reactant has been reduced? Explain your choice.
46. Consider the following equation: Ca(s) + Hg2+(aq)  Ca2+(aq) + Hg()
a. Which reactant has been oxidized? Explain.
b. Which reactant has been reduced? Explain.
47. Write an equation for the oxidation of Al metal by Cr3+ ions.
48. Write an equation for the reduction of Mn2+ ions by Mg metal.
Unit 2.C Minerals and Moles
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