1. Chapter 5 Chemical Quantities and Reactions
5.1
The Mole
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2. Collection Terms A collection term states a specific number of items.
1 dozen donuts
= 12 donuts
1 ream of paper
= 500 sheets
1 case = 24 cans
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3. A Mole of Atoms A mole is a collection that contains
the same number of particles as there are carbon atoms in 12.0 g of carbon.
6.02 x 1023 atoms of an element (Avogadro’s number).
1 mole element Number of Atoms
1 mole C = x 1023 C atoms
1 mole Na = x 1023 Na atoms
1 mole Au = x 1023 Au atoms

4. A Mole of a Compound A mole
of a covalent compound has Avogadro’s number of molecules.
1 mole CO2 = x 1023 CO2 molecules
1 mole H2O = x 1023 H2O molecules
of an ionic compound contains Avogadro’s number of formula units.
1 mole NaCl = 6.02 x 1023 NaCl formula units
1 mole K2SO4 = 6.02 x 1023 K2SO4 formula units

5. Samples of 1 Mole Quantities
1 mole of C atoms = 6.02 x 1023 C atoms 1 mole of Al atoms = 6.02 x 1023 Al atoms 1 mole of S atoms = 6.02 x 1023 S atoms 1 mole of H2O molecules = 6.02 x 1023 H2O molecules 1 mole of CCl4 molecules = 6.02 x 1023 CCl4 molecules

6. Avogadro’s Number Avogadro’s number, 6.02 x 1023, can be written as an
equality and two conversion factors.
Equality:
1 mole = x 1023 particles
Conversion Factors:
6.02 x 1023 particles and mole
1 mole x 1023 particles

7. Using Avogadro’s Number
Avogadro’s number is used to
convert moles to particles
convert particles to moles
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8. Converting Moles to Particles
Avogadro’s number is used to convert
moles of a substance to particles.
How many Cu atoms are in 0.50 mole of
Cu?
0.50 mole Cu x x 1023 Cu atoms
1 mole Cu
= 3.0 x 1023 Cu atoms
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9. Converting Particles to Moles
Avogadro’s number is used to convert
particles of a substance to moles.
How many moles of CO2 are in
2.50 x 1024 molecules CO2?
2.50 x 1024 molecules CO2 x mole CO2
6.02 x 1023 molecules CO2
= moles of CO2

10. Learning Check
1. The number of atoms in 2.0 mole of Al atoms is A. 2.0 Al atoms. B. 3.0 x 1023 Al atoms. C. 1.2 x 1024 Al atoms. 2. The number of moles of S in 1.8 x 1024 atoms of S is A. 1.0 mole of S atoms. B. 3.0 moles of S atoms. C. 1.1 x 1048 moles of S atoms.

11. Subscripts and Moles The subscripts in a formula show
the relationship of atoms in the formula.
the moles of each element in 1 mole of compound.
Glucose
C6H12O6
In 1 molecule: 6 atoms C 12 atoms H 6 atoms O
In 1 mole: 6 moles C 12 moles H 6 moles O

12. Subscripts State Atoms and Moles
9 moles of C 8 moles of H moles of O

13. Factors from Subscripts
The subscripts are used to write conversion factors for moles of each element in 1 mole of a compound. For aspirin, C9H8O4, the possible conversion factors are: 9 moles C 8 moles H 4 moles O 1 mole C9H8O4 1 mole C9H8O4 1 mole C9H8O4 and 1 mole C9H8O4 1 mole C9H8O4 1 mole C9H8O4 9 moles C 8 moles H 4 moles O

14. Learning Check
A. How many moles of O are in mole of aspirin, C9H8O4? B. How many atoms of O are in mole of aspirin, C9H8O4?

15. Chapter 5 Chemical Quantities and Reactions
5.2
Molar Mass
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16. Molar Mass The molar mass
is the mass of 1 mole of an element or compound.
is the atomic or molecular mass expressed in grams.
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17. Molar Mass from Periodic Table
is the atomic mass expressed in grams.
1 mole of Ag mole of C mole of S
= g = g = g
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18. Learning Check
Give the molar mass for each (to the tenths decimal place). A. 1 mole of K atoms = ________ B. 1 mole of Sn atoms = ________

19. Molar Mass of a Compound
The molar mass of a compound is the sum of the molar masses of the elements in the formula. Example: Calculate the molar mass of CaCl2.
Element
Number of Moles
Atomic Mass
Total Mass Ca 1
40.1 g/mole
40.1 g Cl 2
35.5 g/mole
71.0 g
CaCl2
111.1 g

20. Molar Mass of K3PO4 Calculate the molar mass of K3PO4. Element
Number of Moles
Atomic Mass
Total Mass in K3PO4 K P O

21. Some 1-mole Quantities 32.1 g 55.9 g 58.5 g 294.2 g 342.2 g
One-Mole Quantities
32.1 g g g g g
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22. Learning Check
What is the molar mass of each of the following? A. K2O B. Al(OH)3

23. Learning Check
Prozac, C17H18F3NO, is an antidepressant that inhibits the uptake of serotonin by the brain. What is the molar mass of Prozac?
1) g/mole
2) 262 g/mole
3) 309 g/mole

24. Molar Mass Factors Molar mass conversion factors
are fractions (ratios) written from the molar mass.
relate grams and moles of an element or compound.
for methane, CH4, used in gas stoves and gas heaters is
1 mole of CH4 = g (molar mass equality)
Conversion factors:
16.0 g CH and mole CH4
1 mole CH g CH4

25. Learning Check
Acetic acid, C2H4O2, gives the sour taste to vinegar. Write two molar mass conversion factors for acetic acid.
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26. Calculations Using Molar Mass
Molar mass factors are used to convert between the grams of a substance and the number of moles.
Molar mass factor
Grams
Moles

27. Moles to Grams
Aluminum is often used to build lightweight bicycle frames. How many grams of Al are in 3.00 mole of Al? Molar mass equality: 1 mole of Al = 27.0 g of Al Setup with molar mass as a factor: 3.00 mole Al x 27.0 g Al = 81.0 g of Al 1 mole Al molar mass factor for Al

28. Learning Check
Allyl sulfide, C6H10S, is a compound that has the odor of garlic. How many moles of C6H10S are in 225 g?
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29. Grams, Moles, and Particles
A molar mass factor and Avogadro’s number convert…

30. Learning Check
How many H2O molecules are in 24.0 g of H2O? 1) 4.52 x 1023 H2O molecules 2) 1.44 x 1025 H2O molecules 3) 8.03 x 1023 H2O molecules

31. Learning Check
If the odor of C6H10S can be detected from 2 x g in 1 liter of air, how many molecules of C6H10S are present?

32. Chapter 5 Chemical Quantities and Reactions
5.3 Chemical Changes
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33. Physical Change In a physical change,
the state, shape, or size of the material changes.
the identity and composition of the substance do not change.
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34. Chemical Change In a chemical change,
reacting substances form new substances with different compositions and properties.
a chemical reaction takes place.
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35. Some Examples of Chemical and Physical Changes
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36. Learning Check
Classify each of the following as a 1) physical change or 2) chemical change. A. ____Burning a candle. B. ____Ice melting on the street. C. ____Toasting a marshmallow. D. ____Cutting a pizza. E. ____Polishing a silver bowl.

37. Chemical Reaction In a chemical reaction
a chemical change produces one or more new substances.
there is a change in the composition of one or more substances.
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38. Chemical Reaction In a chemical reaction
old bonds are broken and new bonds are formed.
atoms in the reactants are rearranged to form one or more different substances.

39. Chemical Reaction In a chemical reaction the reactants are Fe and O2.
the new product Fe2O3 is called rust.
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40. Chapter 5 Chemical Quantities and Reactions
5.4
Chemical Equations
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41. Chemical Equations A chemical equation gives
the formulas of the reactants on the left of the arrow.
the formulas of the products on the right of the arrow.
Reactants Product
O2 (g)
CO2 (g)
C(s)
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42. Symbols Used in Equations
Symbols in chemical
equations show
the states of the reactants.
the states of the products.
the reaction conditions.
TABLE

43. Chemical Equations are Balanced
In a balanced
chemical reaction
no atoms are lost or gained.
the number of reacting atoms is equal to the number of product atoms.
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44. A Balanced Chemical Equation
In a balanced chemical equation,
the number of each type of atom on the reactant side is equal to the number of each type of atom on the product side.
numbers called coefficients are used in front of one or more formulas to balance the number of atoms.
Al S Al2S Not Balanced
2Al S Al2S3 Balanced using coefficients
2 Al = 2 Al Equal number of Al atoms
3 S = 3 S Equal number of S atoms

45. A Study Tip: Using Coefficients
When balancing a chemical equation,
use one or more coefficients to balance atoms.
never change the subscripts of any formula.
N O NO Not Balanced
N O N2O2 Incorrect formula
N O NO Correctly balanced
using coefficients

46. Learning Check State the number of atoms of each element on the
reactant side and the product side for each of the
following balanced equations.
A. P4(s) Br2(l) PBr3(g)
B. 2Al(s) Fe2O3(s) Fe(s) Al2O3(s)

47. Learning Check Determine if each equation is balanced or not.
A. Na(s) N2(g) Na3N(s)
B. C2H4(g) H2O(l) C2H6O(l)

48. Steps in Balancing an Equation
To balance the following equation,
Fe3O4(s) H2(g) Fe(s) H2O(l)
work on one element at a time.
use only coefficients in front of formulas.
do not change any subscripts.
Fe: Fe3O4(s) H2(g) Fe(s) H2O(l)
O: Fe3O4(s) + H2(g) Fe(s) H2O(l)
H: Fe3O4(s) + 4H2(g) Fe(s) H2O(l)

49. Balancing Chemical Equations
1. Write the equation with the correct formulas.
NH3(g) O2(g) NO(g) H2O(g)
2. Determine if the equation is balanced.
No, H atoms are not balanced.
3. Balance with coefficients in front of formulas.
2NH3(g) O2(g) NO(g) H2O(g)
Double the coefficients to give even number of O atoms.
4NH3(g) O2(g) NO(g) H2O(g)

50. Balancing Chemical Equations
4. Check that atoms of each element are equal in reactants and products.
4NH3(g) O2(g) NO(g) H2O(g)
4 N (4 x 1 N) = N (4 x 1 N)
12 H (4 x 3 H) = 12 H (6 x 2 H)
10 O (5 x 2 O) = 10 O (4 O + 6 O)

51. Equation for a Chemical Reaction
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52. Checking a Balanced Equation
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Reactants Products
1 C atom = 1 C atom
4 H atoms = 4 H atoms
4 O atoms = 4 O atoms

53. Learning Check Check the balance of atoms in the following:
Fe3O4(s) H2(g) Fe(s) H2O(l)
A. Number of H atoms in products.
1) 2 2) 4 3) 8
B. Number of O atoms in reactants.
C. Number of Fe atoms in reactants.
1) 1 2) 3 3) 4

54. Learning Check
Balance each equation and list the coefficients in the balanced equation going from reactants to products:
A. __Mg(s) + __N2(g) __Mg3N2(s)
1) 1, 3, ) 3, 1, ) 3, 1, 1
B. __Al(s) + __Cl2(g) __AlCl3(s)
1) 3, 3, 2 2) 1, 3, ) 2, 3, 2

55. Equations with Polyatomic Ions
2Na3PO4(aq) + 3MgCl2 (aq) Mg3 ( PO4(s) + 6NaCl(aq)
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56. Balancing with Polyatomic Ions
Na3PO4(aq) + MgCl2(aq) Mg3(PO4)2(s) + NaCl(aq)
Balance PO43- as a unit
2Na3PO4(aq) + MgCl2(aq) Mg3(PO4)2(s) + NaCl(aq)
2 PO = PO43-
Check Na + balance
6 Na = Na+
Balance Mg and Cl
2Na3PO4(aq) + 3MgCl2(aq) Mg3(PO4)2(s) + 6NaCl(aq)
3 Mg = 3 Mg2+
6 Cl = Cl-

57. Learning Check
Balance and list the coefficients from reactants to products.
A. __Fe2O3(s) __C(s) __Fe(s) __CO2(g)
1) 2, 3, 2, ) 2, 3, 4, ) 1, 1, 2, 3
B. __Al(s) + __FeO(s) __Fe(s) __Al2O3(s)
1) 2, 3, 3, ) 2, 1, 1, ) 3, 3, 3, 1
C. __Al(s) + __H2SO4(aq) __Al2(SO4)3(aq) + __H2(g)
1) 3, 2, 1, ) 2, 3, 1, ) 2, 3, 2, 3