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Name: ________________________________________________ Textbook Notes Unit 2 and small part of Unit 1 Term 1 2017
Materials: Structure and UsesUNIT 2 A.1 pg. 110-111A physical property is __________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
List examples of physical properties: 1. _____________________________
2.____________________________________ 3._________________________________
A physical change is __________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
List examples of physical changes: 1. _____________________________
2.____________________________________ 3._________________________________
A chemical change is __________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Chemical properties are _________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
In your own words, explain chemical change and chemical properties in terms of how they relate to rusting of a metal.
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
A.1–A.3 Content Reading Guide: Physical and Properties
As you read, list at least five physical and three chemical properties and give specific examples of each property.
Physical Properties Specific Example
Chemical Properties Specific Examples
2
A.1 Supplement: Physical and Chemical Properties
Physical properties are properties that can be determined without altering the chemical makeup of a substance. Chemical properties relate to the types of chemical changes that a substance undergoes (or doesn’t undergo).
Using the space provided, classify each of the following statements as describing either a chemical property or a physical property.
1. Gallium, used primarily in semiconductors and light emitting diodes (LEDs), is a soft, silver-colored metal.
___________________
2. Helium is used to fill blimps because its density is lower than that of air, thus enabling these crafts to float.
___________________
3. Zinc metal burns in air to form zinc oxide.
___________________
4. Sodium metal must be stored under kerosene or nitrogen because of its high reactivity with oxygen and water.
___________________
5. Bromine is a reddish-brown element, is the only nonmetallic element that exists in the liquid state at room temperature.
___________________
6. Isopropyl alcohol (also known as rubbing alcohol) readily evaporates when it is placed on your skin.___________________
7. Carbon dioxide and water are produced when gasoline undergoes combustion in a car engine.
___________________
8. More energy is needed to raise the temperature of 1 g of water than is needed to raise the temperature of 1 g of any metal
___________________
9. The compound boron nitride is almost as hard as diamond and is used for glass and diamond shaping and cutting.
___________________
10. Hydrogen sulfide is removed from the natural gas used to heat homes through a reaction with oxygen.
___________________
3
A.2 Read Developing Skills Physical and Chemical Properties pg. 111-112
Write the answers to questions 1-9 by classifying each as a physical or chemical property.
1. Pure metals have a high luster ____________________________
2. The surfaces of some metals become dull when exposed ____________________________ to air.
3. Nitrogen gas, which is a relatively nonreactive element ____________________________ at room temperature, can form nitrogen oxides at the high temperatures of an operation automobile engine.
4. Milk turns sour if left too long at room temperature. ____________________________
5. Diamonds are hard enough to be used as a coating for ____________________________ drill bits.
6. Metals are typically ductile. ____________________________
7. Leavened bread dough increases in volume if it is ____________________________ allowed to rise before baking.
8. Unreactive argon gas, rather than air, is used to fill ____________________________ many light bulbs to prevent the metal filament wire inside the bulb from being destroyed through oxidation.
9. Generally, metals are better conductors of heat and ____________________________ and electricity than are nonmetals.
A. 4 pg. 114
All matter is composed of ______________________________________. Explain why one element differs from another:______________________________________________________________________________
______________________________________________________________________________
In general, how many chemical elements are known? __________________________________
Similarities and differences in the properties of elements are used to do what to the elements?
______________________________________________________________________________
What are the two major classes of elements? ________________________________
4
________________________________Some examples of metals include iron (Fe), tin (Sn), aluminum (Al), and copper (Cu). Based on your previous knowledge of these metals, give some physical properties of metals. Include state of matter.___________________________________ ____________________________________
____________________________________ ____________________________________
Some examples of nonmetals include carbon (C), oxygen (O), and sulfur (S). Based on your previous knowledge of these non-metals, give some physical properties of non-metals. Include state(s) of matter.
___________________________________ ____________________________________
____________________________________ ____________________________________
Explain what you would expect from an element that is a metalloid.
______________________________________________________________________________
______________________________________________________________________________
A. 6 pg. 117-119
What is the periodic table used for?
______________________________________________________________________________
______________________________________________________________________________
Who is credited with publishing the periodic table in use today?
____________________________________
Why is the periodic table in use today similar to moon-phase calendar? (see Fig. 2.9)
______________________________________________________________________________
______________________________________________________________________________
Describe the two characteristics of elements used in the 1800s to organize periodic tables.
______________________________________________________________________________
______________________________________________________________________________
5
A. 8 pg. 120-121
What do we now expect of all elements found in the leftmost column of the periodic table?
______________________________________________________________________________
What about the ones in the rightmost column?_________________________________________
Name the three smaller particles that compose atoms. Write the charge above the name. Fig. 2.11
________________________ _______________________ ___________________________
What does the atomic number identify? _____________________________________________
What does atomic number have to do with the way the modern periodic table is organized?
______________________________________________________________________________
If an atom is electrically neutral, it must have equal parts of which two particles written above?
________________________ _______________________
Look at the periodic table in the back cover of your book:If the number of protons in an atom is 10, what element is it? ________________________
If the atomic number is 20, what element is it? ________________________
Which two particles written above are found in the nucleus?
________________________ _______________________
Which two particles written above are combined to make the mass number?
________________________ _______________________
Therefore the mass number is the mass of the nucleus!!
Why doesn’t the mass of the electron contribute to the mass of the atom?
______________________________________________________________________________
______________________________________________________________________________
What is an isotope? ____________________________________________________________
6
A.8 Supplement: The Pattern of Atomic Numbers
Using a periodic table, fill in the chart with the correct information. Assume that all atoms are electrically neutral.
Name Symbol Atomic Number
Mass Number
# of Protons
# of Neutrons
# of Electrons
1. boron B 5 11 5 6 52. zinc 31
3. K 42
4. 22 27
5. 122 51
6. U 146
7. 47 60
8. fermium 257
9. cesium 79 55
10. 42 97
11. 120 78
12. krypton 47
13. 86 222
14. N 15
15. 7 7
16. What similarities exist between the answers to questions 14 and 15 on the table?
_____________________________________________________________________________________
_____________________________________________________________________________________
17. What differences exist between the answers to questions 14 and 15 on the table?
_____________________________________________________________________________________
_____________________________________________________________________________________
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18. What term can be applied to atoms like those described in questions 14 and 15 on the table?_____________________________________________________________________________________
_____________________________________________________________________________________
19. What is the difference between mass number (used in this exercise) and atomic weight (found on the periodic table)?_____________________________________________________________________________________
_____________________________________________________________________________________
A. 10 pg. 125
Explain the difference on the periodic table between periods and groups.
______________________________________________________________________________
______________________________________________________________________________
What is the name for most of the elements found in the leftmost column of the periodic table?
______________________________________________________________________________
Which element in this column is not part of this group? ________________________________
What about the ones in the rightmost column?_________________________________________
What about the column to the left of the one named above? ______________________________
Find fluorine (atomic number 9) on the periodic table. If you know some of the properties of fluorine, what can be said about the properties of chlorine (atomic number 17)?
______________________________________________________________________________
______________________________________________________________________________
A. 11 Answer the questions to Predicting Properties on pg. 126
1. Estimate the boiling point of krypton. __________________
Explain how you got your answer: _________________________________________________
______________________________________________________________________________
2. (a) Estimate the melting point of rubidium. __________________ (b) Do you expect the melting point of sodium to be higher or lower
than rubidium? __________________On what evidence did you base your answer? (Write answer in space below)
8
A.11 Supplement: Predicting PropertiesGiven these known compounds—CO2, KF, MgO, CaCl2, Na2O, Ga2O3, and AlCl3—predict the formulas for the following combinations of elements.
1. a) Si and O _________________ b) Ba and S _________________
2. a) K and S __________________ b) B and F __________________
3. a) Li and Br _________________ b) Sr and O _________________
4. a) In and I __________________ b) Ca and F _________________
5. a) Al and S __________________ b) H and O __________________
6. Given that the density of helium (He) is 0.1785 g/cm3 and the density of argon (Ar) is 1.784 g/cm3, estimate the density of neon.
7. Would you expect the density of krypton (Kr) to be higher or lower than that of argon (Ar)? Explain your answer.
_________________________________________________________________________________
_________________________________________________________________________________
8. Given that the boiling point of nickel (Ni) is 3003 K and the boiling point of platinum (Pt) is 3560 K, estimate the boiling point of palladium (Pd).
9. Are the chemical properties of sodium more likely to be similar to potassium or magnesium? Explain._________________________________________________________________________________
_________________________________________________________________________________
10. Discovery of element 113 has not yet been proven or verified. Assuming its discovery is accepted some day, what would you expect the approximate atomic mass to be? Explain. (Answer in space below)
9
An alphabetical chart of the elements is found on pgs 129-130.
UNIT 1 B.3 pg. 28-30 Start on section Mixtures and Solutions
How can the components of a mixture be separated? ___________________________________
______________________________________________________________________________
Describe a heterogeneous mixture. Explain how you know it is heterogeneous.
______________________________________________________________________________
______________________________________________________________________________
Describe a suspension. Explain how you know it is a suspension.
______________________________________________________________________________
______________________________________________________________________________
Describe a colloid. Explain how you know it is a colloid.
______________________________________________________________________________
______________________________________________________________________________
Describe a homogenous mixture. Explain how you know it is homogeneous.
______________________________________________________________________________
______________________________________________________________________________
In a salt water solution, what part is the solute? ________________________
what part is the solvent? ________________________Use figure 1.24 to help classify the following types of matter as Element, Compound, Solution, Colloid, SusPensionunopened soda (water, sugar, CO2, etc.) ____________________
water (H2O) ____________________
bromine (Br) ____________________
orange juice (water, citric acid and organic matter) ____________________
milk (water, fats, organic materials) ____________________
10
B.4 pg. 31Why are atoms known as the building blocks of matter?
______________________________________________________________________________
Give an example of each and explain the difference between an element and a compound.
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
What are two reasons why elements and compounds are considered substances?
______________________________________________________________________________
______________________________________________________________________________
What holds the atoms of a molecule together? ________________________________________
Study Guide Test Section A
1. Identify each chemical and physical property of calcium that is described in the following paragraph.
Calcium is a shiny, silvery-white metal. When it is exposed to moist air, it readily tarnishes. At room temperature, calcium exists in the solid state and its melting point is 842 °C. It reacts with acid and with water to yield hydrogen gas.
Chemical Properties:
Physical Properties:
2. Analyze the following data and classify each substance as a metal, nonmetal, or metalloid.
Element Malleable or Brittle/Color?
Shiny or Dull? Conductor? Reacts with
Acid?Metal, Nonmetal, or
Metalloid?
A brittle/yellow dull yes no
B malleable/silver shiny yes yes
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C brittle/grey dull no no
D brittle/black dull yes no
E malleable/grey shiny yes yes
3. Name the family to which each element belongs:
a. K ________________________________ Be _________________________________
b. Kr________________________________ I___________________________________
The melting point of Fluorine is –219 C while that of bromine is –7.3 C. Estimate the melting point of chlorine. Explain how you arrived at your estimation.
_________________________________________________________________________________
_________________________________________________________________________________
4. Given a periodic table and the formulas Na2O and Ca3P2, predict the formula for a compound containing:
a. Li and S _____________ b. Mg and N_____________
5. Complete the following table:
Element Symbol Atomic Number
Number of Protons
Number of Neutrons
Mass Number
Neon 20
6 8
7 14
Na 23
6. An atom of element X has 6 protons and 6 neutrons. Is an atom that has 6 protons and 10 neutrons an isotope of element X? Explain. _________________________________________________________________________________
_________________________________________________________________________________
12
7. Identify the element that is described by each of the following statements:a. This element is a metal. It is in the alkaline metals group and in the same period as the metals
used in a penny._______________________________
b. This element is a metalloid. It is in the same period as the element found in cans used for soft drinks and other food items.
_______________________________
8. Why is knowledge of the chemical and physical properties of matter important in the coin design process?
_________________________________________________________________________________
_________________________________________________________________________________
Section B.3-B.4 Study GuideComplete each of the following questions.
1. What physical properties would allow you to distinguish between liquid water and rubbing alcohol?
___________________________________________________________________________
___________________________________________________________________________
2. Carbon tetrachloride, CCl4 is a liquid that can be used in dry cleaning. When 5.0 g of bromine is added to 75 g of clear colorless CCl4, the mixture has a reddish-brown color. Over time, no settling out is observed. When the mixture is filtered, no residue is observed on the filter paper. When a light beam is directed at the mixture, its path through the mixture is not visible. Is the mixture a solution, colloid or suspension? Explain your answer.
___________________________________________________________________________
___________________________________________________________________________
3. Draw a model of a solution in which water (H2O) is the solvent and carbon dioxide gas (CO2) is the solute.
4. Classify each of the following as an element or a compound.
a. NaCl ___________________________ b. C ___________________________________
c. CO ___________________________ d. KNO3 _______________________________
5. Draw a model of a molecular compound made up of two atoms of B and two atoms of E.
13
B.4, B.6 & B.9 Content Reading Guide: Particulate View of Matter
Compare elements and compounds using this chart.
Element Compound
Smallest particleTwo types:
Represented by
How many are found in nature?
Examples (at least 4 for each)
14
B.6 Answer these questions after reading the material on pg. 34-35 The chemical formulas of common compounds are listed below. Explain how many of each element is found in the compound.
table salt NaCl (sodium chloride) ___________ sodium ___________ chlorine
baking soda NaHCO3 (sodium bicarbonate) ____ sodium ____ hydrogen ____ carbon ____ oxygen
chalk CaCO3 (calcium carbonate) _______ calcium ________ carbon _______ oxygen
table sugar (sucrose) C12H22O11 ________ carbon________ hydrogen _______ oxygen
octane (found in gasoline) C8H18 ________ carbon________ hydrogen
Label the reactants and the products for the reaction of the combustion of gasoline in your car:
2C8H18(l) + 25O2(g) 16CO2(g) + 18H2O (l)
count how many atoms on each side: Like math, distribute the number in front of the formula.
___C ___H ___O ___C ___H ___O Do the amounts match? ___________
Copy the information from Table 1.3
ELEMENTS THAT EXIST AS DIATOMIC MOLEULESElement Formula Element Formula
B.7 Use the periodic table or the table of elements to answer the questions 1. Name the element represented by each of these symbols:
i. P ____________________________ v. Br _______________________________
ii. Ni ____________________________ vi. K _______________________________
iii. Cu ____________________________ vii. Na _______________________________
15
b. Which elements in question 1 have symbols that correspond to their English names?
______________________________________________________________________________
______________________________________________________________________________
c. Which is more likely to be the same throughout the world, an element’s symbol or its name? Explain.
______________________________________________________________________________
______________________________________________________________________________
2. Name the elements and give the number of atoms of each element:Element Names Amount of each Element
H2O2 H:
O
H:
O:CaCl2 Ca:
Cl:
Ca:
Cl:H2SO4 H:
S:
O:
H:
S:
O:
3. CH4(l) + 2O2(g) CO2(g) + 2H2O (l) a. Write a sentence describing the equation in terms of molecules. Use the words reactant and products and the specific names that the formulas stand for.
______________________________________________________________________________
______________________________________________________________________________
b. Identify the molecules as either an element or a compound. You can do this above the formulas.
c. Count the number of each element on each side of the reaction. (atom inventory) Remember, the big numbers (coefficients) are distributed to each element in the formula.
do they match? yes or noC: _______ C: _______ _____________H:_______ H:_______ _____________O: _______ O:_______ _____________
16
B.8 pg. 37-38
List two every day examples that show the electrical nature of matter:
______________________________________________________________________________
______________________________________________________________________________
Summarize the electrical properties of matter using words and an illustration: [ fig at top of pg 38]
Name the parts of an atom and state their charges:
part charge
B.9 pg. 38-41
What is an ion? ________________________________________________________________
______________________________________________________________________________
What makes an ionic compound neutral? ____________________________________________
_____________________________________________________________________________
Explain how anions and cations are different. In your description, be sure to clearly explain what makes each different from the other.
______________________________________________________________________________
______________________________________________________________________________
What is a polyatomic ion? _______________________________________________________
17
B.10 pg. 41Fill in the table after reading the descriptions of the compounds in statements 1-6
Cation Anion Formula Name1.
2.
3.
4.
5.
6.
B.9 & B.10 Supplement: Ions and Ionic Compounds
Complete the data table identifying the composition of each ionic compound. Names and formulas of polyatomic ions can be found in Table 1.4 of your textbook.
Remember these rules as you write formulas for ionic compounds: Write the cation first, and then write the anion. The correct formula will contain the fewest positive and negative ions needed to make the total electrical
charge zero.As you write the names of ionic compounds, remember to: Write the name of the cation first, and then write the anion name. Some metal atoms form ions with different charges under different conditions. To specify the charge for these
ions, Roman numerals are used in parentheses after the name of the metal. These include: copper, lead, iron, mercury.
Anions composed of a single atom have the last few letters of the element’s name changed to the suffix –ide.
Cation Anion Formula Name1. calcium oxide
2. NaCl
3. NH4+ NO3
-
4. Cu(OH)2
5. iron(III) sulfate
18
6. K+ SO32-
7. Na3PO4
8. silver sulfide
9. Zn2+ Br-
10. barium fluoride
11. Al3+ PO43-
12. K2S
13. magnesium oxide
14. Ba2+ SO42-
15. zinc phosphate
16. Ca2+ HCO3-
17. FeCl3
18. lead(ii) carbonate
19. Pb2+ Br-
20. LiNO3
UNIT 2 C.1 pg. 153
19
Explain the law of conservation of matter in your own words:
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
C.1 Supplement: Keeping Track of Atoms1. A chemical equation is balanced if there are ___________________________ of each kind
of___________________________on both sides of the equation.
2. Accounting for atoms: determine the number of atoms of each kind in each of the following:
a. CaCO3 = ______ Ca ______ C ______ O
b. (NH4)2SO4 = ______ N ______ H ______ S ______ O
c. 3 H2 = ______ H
d. 4 Mg(OH)2 = ______ Mg ______ O ______ H
e. Ba(NO3)2 = ______ Ba ______ N ______ O
3. For each equation, list the number of each type of atom shown on the reactant side and the product side of the arrow. Also indicate whether the overall equation is balanced.
a. 2 Na + 2 H2O → 2 NaOH + H2
Reactants Products
_____________ Na _____________
_____________ H _____________
_____________ O ________________ Balanced? Yes ____ No____
b. 4 NH3 + 6 NO → 5 N2 + 6 H2OReactants Products
_____________ N _____________
_____________ H _____________
_____________ O ______________ Balanced? Yes ____ No____
c. NaCl + F2 → NaF + Cl2
20
_____________ Na _____________
_____________ Cl _____________
_____________ F ______________ Balanced? Yes ____ No____
d. 3 NaBr + H3PO4 → 2 HBr + Na3PO4
_____________ Na _____________
_____________ Br _____________
_____________ H _____________
_____________ P _____________
_____________ O _____________ Balanced? Yes ____ No____
e.N2H4 + N2O4 → 3 N2 + 4 H2O Balanced? Yes ____ No____
f.4 Ag + 4 H2S + O2 → 2 Ag2S + 4 H2O Balanced? Yes ____ No____
g.2 Bi + 3 F2 → 2 BiF3 Balanced? Yes ____ No____
h.Al + Ni(NO3)2 → Al(NO3)3 + Ni Balanced? Yes ____ No____
21
i.3 NaBH4 + 4 BF3 → 2 B2H6 + 3 NaBF4 Balanced? Yes ____ No____
j.4 C3H5(NO3)3 → 6 N2 + O2 + 12 CO2 + 10 H2O Balanced? Yes ____ No____
k.Ca10F2(PO4)6 + 7 H2SO4 → 2 HF + 3 Ca(H2PO4)2 + 7 CaSO4
Balanced? Yes ____ No____
C.2 Read Developing Skills Accounting for Atoms pg. 155-157Write the answers to questions1-5. For each question, (a) write an interpretation of the statement in words (b) omit (c) complete an atom inventor, (d) decide if it is balanced. There are answers to the sample question that can be used if you need help.
1. CH4 + 2O2 CO2 + 2H2O(a) __________________________________________________________________________
______________________________________________________________________________
(c) C: _______ C: _______H:_______ H:_______O: _______ O:_______ (d) balanced? _________________________
2. HBr + Mg H2 + MgBr2
(a) __________________________________________________________________________
______________________________________________________________________________
(c) Br: _______ Br: _______H:_______ H:_______Mg: _______ Mg:_______ (d) balanced? _________________________
22
3. 4 Ag + 4 H2S + O2 2Ag2S + 4H2O(a) __________________________________________________________________________
______________________________________________________________________________(c) Ag: _______ Ag: _______
H:_______ H:_______S: _______ S:_______O: _______ O:_______ (d) balanced? _________________________
4. C6H10O5 + 6O2 6CO2 + 5H2O(a) __________________________________________________________________________
______________________________________________________________________________
(c) C: _______ C: _______H:_______ H:_______O: _______ O:_______ (d) balanced? _________________________
5. 2C3H5(NO3)3 3N2 + O2 +6CO2 + 5H2O(a) __________________________________________________________________________
______________________________________________________________________________
(c) C: _______ C: _______H:_______ H:_______O: _______ O:_______ (d) balanced? _________________________
C.3 pgs. 157-159 All chemical changes can be interpreted as what? ______________________
______________________________________________________________________________
What happens when the subscript in a chemical formula is changed? ______________________
______________________________________________________________________________
What part of the chemical equation is adjusted to balance the equation? ____________________
Write the three suggestions to help you correctly balance equations:
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
23
C.3 Supplement: Nature’s Conservation—Balanced Chemical Equations
Balance the following equations.
1. _____H2 + _____O2 → _____H2O
2. _____Mg + _____O2 → _____MgO
3. _____Ca + _____H2O → _____Ca(OH)2 + _____H2
4. _____Cu + _____HgNO3 →_____Cu(NO3)2 + _____Hg
5. _____C3H8 + _____O2 → _____CO2 + _____H2O
6. _____Al + _____F2 →_____AlF3
7. _____Fe + _____O2 →_____Fe2O3
24
8. _____Fe3O4 + _____H2 →_____Fe + _____H2O
9. _____HBr +_____ O2 →_____Br2 + _____H2O
10. _____Al2O3 + _____HCl→_____AlCl3 + _____H2O
11. _____NH4OH + _____FeCl3→ _____Fe(OH)3 + _____NH4Cl
12. _____NH3 + _____O2 →_____NO +_____ H2O
13. _____I2 + _____HNO3→_____HIO3 + _____NO2 + _____H2O
14. _____CaO + _____P2O5→_____Ca3(PO4)2
15. _____NaOH + _____Al2(SO3)3→_____Na2SO3 + _____Al(OH)3
25
C.4 159-161
Correctly balance the following equations. Perform an atom inventory at the end to make sure it is correct.1. a. C(s) + O2(g) 2CO(g)
b. Fe2O3(s) + CO(g) Fe(l) + 3 CO2(g)
2. CuO(s) + C(s) Cu(s) + CO2(g)
3. O3(g) O2(g)
4. NH3(g) + O2(g) NO2(g) + H2O(l)
5. Cu(s) + AgNO3(aq) Cu(NO3)2(aq) + Ag(s)
6. C8H18(l) + O2(g) CO2(g) + H2O(g)
C.5 p. 161-163
What is the name and symbol for the chemist’s dozen? _________________________________
Write Avogodro’s number in scientific notation. ______________________________________
If you wrapped a paper clip chain around the earth that equaled a mole of paperclips, how many times would it go around the earth? ____________
How many grams does one mole of water equal? ____________
What value must be known in order to find themass of one mole of a substance? ____________________________________
Where can you find the numerical value
26
of an element’s atomic weight? ____________________________________C.5 Supplement: Molar Masses
The molar mass of a substance is the mass of one mole (6.02 × 1023 units) of the substance. The mass in grams of one mole of an element’s atoms is equal to the numerical value of that element’s atomic weight. These values for each element can be found on the periodic table.
To find the molar mass of a substance, multiply the number of moles of each element by the molar mass of the element. Then add the masses of the various elements.
Example 1: What is the molar mass of iron(III) oxide, Fe2O3?2 mol Fe = 2 × 55.85 g = 111.7 g Fe3 mol O = 3 × 16.00 g = 48.00 g OMolar Mass of Fe2O3 = (111.7 g Fe + 48.00 g O) = 159.7 g Fe2O3
Example 2: What is the molar mass of magnesium hydroxide, Mg(OH)2?1 mol Mg = 1 × 24.31 g = 24.31 g Mg2 mol O = 2 × 16.00 g = 32.00 g O2 mol H = 2 × 1.008 g = 2.016 g HMolar Mass of Mg(OH)2 = (24.31 g + 32.00 g + 2.016 g) = 159.7 g Mg(OH)2
Determine the molar mass of each substance.
27
1. fluorine gas: F2
2. copper (II) chloride: CuCl2
3. aluminum oxide: Al2O3
4. potassium hydroxide: KOH
5. sodium bicarbonate: NaHCO3
6. calcium phosphate: Ca3(PO4)2
7. ammonium sulfate: (NH4)2SO4
8. malachite: Cu2CO3(OH)2
9.alum: KAl(SO4)2• 12H2O
10. glucose: C6H12O
28
C.6 pg. 163 Fill in the table with the chemical formula and the molar mass of each of the following substances:
name formula molar massnitrogen atoms
nitrogen molecules
sodium chloride (table salt)
sucrose (table sugar)
chalcopyrite (copper mineral)
magnesium phosphate
caffeine
calcium hydroxyapatite (a mineral found in teeth)
alunite (aluminum mineral)
C.7 Supplement: Molar Relationships-II
When the molar masses and molar relationships between reactants and products are known, chemists can calculate the amounts of material they need or will produce using a particular reaction.
1. On a small scale, calcium can be isolated through the reaction of calcium chloride with sodium metal, as shown in the following equation:
29
CaCl2 + 2Na → Ca + 2NaCl
a. How many moles of Na are needed to react with 7.00 mol CaCl2?
b. How many moles of NaCl are produced by the reaction of 14.0 mol Na?
c. How many moles of Ca are produced from 3.5 mol Na?
2. Magnetite, an iron ore, can be reduced to form metallic iron by a process called pyrometallurgy. One reaction that occurs during this process is:
Fe3O4 + 4CO → 3Fe + 4CO2
a. How many moles of CO are needed to react with 3.5 mol Fe3O4?
b. How many moles of CO2 are produced by the reaction of 7.00? mol CO? Assume adequate amount of Fe3O4.
c. How many mol of Fe are produced from 5.0 mol CO? Assume adequate amount of Fe3O4.
30
C.7 Supplement: Molar Relationships–IMole-Mass ConversionsOnce the molar mass of a substance is known, it is fairly easy to calculate moles from grams or grams from moles.
Example 1: How many moles are present in 352 g of iron(III) oxide, Fe2O3?
Step 1: Calculate the molar mass of iron (III) oxide.
By adding the mass of two moles of iron atoms and three moles of oxygen atoms, the molar mass is calculated to be 160.0 g.
This can be expressed in two ways as a conversion factor. It is either:a. 160.0 g of Fe2O3 contains 1 mole (160.0 g/1 mol) orb. 1 mole of Fe2O3 contains 160 g (1 mol/160.0 g)
Step 2: Arrange the molar mass so the original units cancel and the desired units are on top.
Example 2: How many grams are present in 1.43 moles of magnesium hydroxide, Mg(OH)2?
Step 1: Calculate the molar mass of magnesium hydroxide.
By adding the mass of one mole of magnesium atoms, two moles of oxygen atoms, and two moles of hydrogen atoms, the molar mass is calculated to be 58.312 g.
Step 2: Arrange the molar mass so the original units cancel and the desired units are on top.
Calculate the following.
1. How many grams equal 1.0 mol of Azurite, Cu3(CO3)2(OH)2,?
2. How many grams equal 6.3 mol of N2?
3. How many moles equal 84.6 g of NaCl?
4. How many moles equal 564 g of C12H22O11?
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5. How many grams equal 3.95 mol of CuFeS2?
6. How many moles equal 0.985 g of Cu2CO3(OH)2 ?
7. How many grams equal 36.5 mol of Cu3(CO3)2(OH)2?
C.1-C.6 REVIEW
There are many important terms introduced in these sections. Define each term in your own words and give an example of what the term would look like in a chemical equation.
Term Definition in Your Own Words ExampleBalanced chemical equation
Law of conservation of mass
Subscript
Coefficient
Formula unit
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Reactant
Product
Mole
Molar mass
The following balanced chemical equation below shows the burning of butane in oxygen. Please label the following parts that are found in the equation, using the letters given to abbreviate.
Subscripts (S) Coefficients (C) Reactants (R) Products (P) Formula units (F)
2 C4H10 + 13 O2 8 CO2 + 10 H2
C.9 pg. 166-168
How can you find the percent composition of a penny?
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Why does percent composition help geologists?
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What two factors must be taken into account when deciding on the quality of a particular ore?
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Percent Composition Developing Skills. Show your work when you perform calculations.
A 90 g sample of limestone is composed of three different elements.
a) Fill in the table for amount of protons and neutrons and calculate the mass number. Then solve for percent abundance. Show your work in the box. Element amount
in sample
percent abundance(round to nearest whole number)element mass divided by sample mass X 100 = %
Calcium 73.7 g
Carbon 7.3 g
Oxygen 9.0 g
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2) A 883 g sample of granite is composed of three different elements. Element amount
in sample
percent abundance
silicon 737.7 g
potassium 27.3 g
aluminum
Content Reading Guide: Chemistry at Work: All That’s Gold Doesn’t Glitter . . . Or Does It? (p. 198-199)
As you read, list and describe the steps used by John Langhans to obtain gold from its ore. Begin your list with the rock deposits, and end with pouring the gold into bar molds.
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Questions to Ponder1. If a 12-karat gold class ring has a mass of 11.2 g, how many metric tons of ore were processed in
order to produce the gold to make the ring?
2. What is the value of the gold in the class ring if the market value of gold is about $10.50/g? (You may want to use the current actual price of gold which is available in the business section of many newspapers or on the World Wide Web.)
3. During the 1800s, gold miners looked for gold in the form of nuggets. What property of gold allows it to be found in this form?
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Study Guide Test Sections B6-B10
1. Complete the following table by naming the elements present and the number of each type of atom.
Compound Element Names Number of Atoms of Each Element
CO2
CaCl2
Al2S3
NH4NO3
2. Write a chemical equation that represents the following word equation:One molecule of nitrogen (N2) reacts with 3 molecules of hydrogen (H2) to form 2 molecules of ammonia (NH3).
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3. Differentiate between protons and electrons in terms of their relative charges.___________________________________________________________________________
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4. Decide whether each of the following atoms is electrically neutral.Element Protons Electrons Neutral?
Gold 79 76
Helium 2 2
Fluorine 9 10
5. Classify the following as anions, cations, or electrically neutral atoms.
a. K+ _____________ b. Ag _____________ c. N3- _____________ d. Ba2+ ___________
6. Write the symbol and show the electrical charge (if any) on the following atoms or ions:
a. helium with one proton and one electron _____________
b. lithium with three protons and two electrons _____________
c. fluorine with nine protons and ten electrons _____________
7. Complete the following table by writing the name and formula for the compound formed from the following ions.
Cation Anion Formula Name37
Mg2+ O2-
Al3+ Cl-
Mg2+ NO3-
NH4+ CO32-
8. As an environmental chemist, you are testing for the presence of chloride ion in samples of stream water. You perform the appropriate test on a sample from Stream A and observe a white precipitate. The same test performed on a sample from Stream B yields no change.a. What is a precipitate?
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b. What can you conclude about the presence of chloride ion in Stream A?c.
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d. Can you make a definite conclusion about the presence of the chloride ion in Stream B? Why or why not?________________________________________________________________________
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Study Guide Test Section C1. How does a balanced chemical equation demonstrate the law of conservation of matter?
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2. For each of the following equations, complete an atom inventory and indicate whether the equation is balanced.a. Rb + RbNO3 → Rb2O + N2
________ Rb________
________ N________
________ O________ Balanced?_____Yes_____No
b. HCl + NaOH → NaCl + H2O________ H________
________ Cl________
________ Na_______
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________ O________
________ H________ Balanced?_____Yes_____No
3. Balance each of these chemical expressions.
a. ____Al2O3 → ____Al + ____O2
b. ____Al + ____S8 → ____Al2S3
c. ____H 3PO4 + ____Mg(OH)2 → ____Mg3(PO4)2 + ____H2O
4. A mole of carbon and a mole of hydrogen have different masses, but both represent 1.00 mol of substance. Explain._________________________________________________________________________________
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5. Find the molar mass of each of the following substances:
a. F2 _____________________________ b. PbS ________________________________
c. MgSO4 ________________________________________________ d. Al(OH)3_______________________________________________
6. For the equation
2C2H6 + 7O2 → 4CO2 + 6H2O
a. How many moles O2 are needed to react with 7.0 mol C2H6?
b. How many moles CO2 are produced by the reaction of 9.0 mol O2?
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c. How many moles H2O are produced from 3.5 mol C2H6?
7. Zinc minerals exist as smithsonite, ZnCO3, at Mining Site A and as sphalerite, ZnS, at Mining Site B. Based only on percent composition of the minerals, at which site would mining of zinc be most feasible?
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8. Why would it be beneficial to know the percent metal in an ore prior to mining?
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9. Differentiate between renewable and nonrenewable resources.
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10. Why are there concerns about the depletion of resources if, as the law of conservation of matter states, matter can neither be created nor destroyed?
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