1. Chapter 9: Chemical Names and Formulas
Sections 1-5 (Read pages )

2. Chapter 9 Vocab Acid Base Binary compound Law of definite proportions
Law of multiple proportions
Monatomic ion
Polyatomic ion

3. Section 9.1: Naming Ions
Read pages

4. Monatomic Ions
Ions that consist of a single atom with a positive or negative charge resulting from the loss or gain of one or more valence electrons
Two Types
Positive Ions
Cations
Negative Ions
Anions

5. Cations Positively charged ions Metal atom loses electrons
Name stays the same
Example:
Name of Element: Aluminum
Number of Valence Electrons: 3
Charge on Ion: +3
Name of Ion: Aluminum

6. Naming Cations Practice
Element
# of Valence Electrons
Ion Formed
Name of Cation
Sodium 1
Na+
Calcium 2
Ca2+
Magnesium
Mg2+
What is the rule for naming cations?
DON’T CHANGE THE NAME.

7. Anions Negatively charged ions Nonmetal atom gains electrons
Name changes to –ide ending
Example:
Name of Element: Iodine
Number of Valence Electrons: 7
Charge on Ion: -1
Name of Ion: Iodide

8. Naming Anions Practice
Element
# of Valence Electrons
Ion Formed
Name of Anion
Nitrogen 5
N3-
Nitride
Sulfur 6
S2-
Sulfide
Fluorine 7 F-
Fluoride
What is the rule for naming anions?
CHANGE THE ENDING TO -IDE

9. Groups 14 (4A) and 18 (8A) usually do not form ions
Note:
Groups 14 (4A) and 18 (8A) usually do not form ions

11. Ions of Transition Metals
Many of the transition metals form more than one cation with different ionic charges
Not all transition metals have more than one charge
Charges must be determined from the number of electrons lost
These colorful solutions contain the transition metal ions Co3+, Cr3+, Fe3+, Ni2+, and Mn2+.

12. Two Methods to Name Transition Metal Ions
Stock System
Classical Method
IUPAC – International Union of Pure and Applied Chemistry

13. Stock System Preferred method of naming
A Roman numeral in parentheses is placed after the name of the element to indicate the numerical value of the charge
Number
Roman Numeral 1 I 2 II 3
III 4 IV 5 V 6 VI

14. Stock System Naming Practice
Ion Formed
# Electrons Lost
Stock Name
Cu+ 1
Copper (I) ion
Cu2+ 2
Copper (II) ion
Pb2+
Lead (II) ion
Pb4+ 4
Lead (IV) ion

15. Classical Method
In the past, scientists used the Latin names of elements.
Example:
Ferrum is Latin for Iron.
Ferr- is the root of this word.
Iron forms two ions: Fe2+ and Fe3+
Ion names:
Fe2+ is the ferrous ion
Fe3+ is the ferric ion

17. Practice Problems
Selenide (anion)
Barium (cation)
Phosphide (anion)

18. Polyatomic Ions What does the prefix poly mean?
MANY
Polyatomic ions are composed of more than one atom
Tightly bound groups of atoms that behave as a unit and carry a charge
The names of most polyatomic ions end in –ite or –ate
Different Endings
Ammonium  NH4+
Cyanide  CN-
Hydroxide  OH-

20. Polyatomic Ions to memorize!
Formula
Name
NO3-
Nitrate
OH-
Hydroxide
ClO3-
Chlorate
SO42-
Sulfate
CO32-
Carbonate
PO43-
Phosphate

21. A closer look at a polyatomic ion
Superscript: shows the charge on the polyatomic ion
Name: Phosphate
PO43-
Subscript: shows the number of atoms of that element
What is the subscript on Phosphorus? 1

22. An important note: Pay close attention to the names! Example:
Sulfide = S2-
Sulfate = SO42-
Sulfite = SO32-

23. Quick Quiz
Section 9.1

24. I only II only III only I and III
1. Which of the following are positively charged polyatomic ions? (I) ammonium ion (II) perchlorate ion (III) iron (II) ion
I only
II only
III only
I and III

25. 2. If the name of an ion ends in -ite or -ate, the ion is a
polyatomic cation.
polyatomic anion.
transition metal cation.
monatomic anion.

26. Section 9.2: Naming and Writing Formulas for Ionic Compounds
Read pages

27. Different Types of Ionic Compounds
Simple Ionic Compounds (last chapter!)
Ionic Compounds Involving Transition Metals
Transition metals with only 1 charge
Transition metals with more than 1 possible charge
Ionic Compounds Involving Polyatomic Ions

28. Binary Ionic Compounds
What does the prefix bi mean?
TWO
A binary ionic compound is composed of two elements - a metal and a nonmetal

29. Naming Binary Ionic Compounds
If you know the formula of the ionic compound, you can write the name
To name any binary ionic compound, place the cation name first, followed by the anion name.

30. Naming Simple Ionic Compounds (last chapter)
1 Metal + 1 Nonmetal
CaCl2
What is the name of the cation?
What is the name of the anion?
Calcium
Chloride

31. Naming Simple Ionic Compounds (last chapter)
1 Metal + 1 Nonmetal
Li2O
What is the name of the cation?
What is the name of the anion?
Lithium
Oxide

32. ZnS Zinc Sulfide WAIT! What’s special about the cation?
Naming Ionic Compounds Containing a Transition Metal with ONE possible charge
1 Transition Metal + 1 Nonmetal
ZnS
WAIT! What’s special about the cation?
Zinc is a transition metal. It has 1 possible charge.
What is the name of the cation?
What is the name of the anion?
We don’t need a Roman numeral because there is only 1 possible charge!
Zinc
Sulfide

33. Cu2O Oxide Copper (I) What’s special about the cation?
Naming Ionic Compounds Containing a Transition Metal with more than one possible charge
1 Transition Metal + 1 Nonmetal
Cu2O
What’s special about the cation?
Copper is a transition metal. It has two possible charges (+1 or +2).
What is the name of the cation?
What is the name of the anion?
Don’t forget the roman numeral!!! (based on oxygen’s charge)
What is the charge on an oxygen ion?
Copper (I)
Oxide 2-

34. CuO Copper (II) Oxide What is the name of the cation?
Naming Ionic Compounds Containing a Transition Metal with more than one possible charge
1 Transition Metal + 1 Nonmetal
CuO
What is the name of the cation?
What is the name of the anion?
Copper (II)
Oxide

35. NaF FeCl3 FeCl2 Sodium Fluoride Iron (III) Chloride Iron (II) Chloride
Try It!
Name the following binary ionic compounds:
NaF
FeCl3
FeCl2
Sodium Fluoride
Iron (III) Chloride
Iron (II) Chloride

36. Writing Binary Ionic Formulas
If you know the name of a binary ionic compound, you can write the formula!
Write the symbol of the cation and then the anion. Then, add the subscripts that are needed to balance the charges.
The positive charge of the cation must balance the negative charge of the anion so that the net ionic charge of the compound is neutral.

37. Remember the crisscross method?
Determine the charge on each ion.
Cross the charges.
Reduce if necessary.
Name the compound.

38. Simple Ionic Compounds Formulas
Write the formula for Sodium Bromide.
First: What is the cation?
Second: What is the anion? - + Na Br
NaBr

39. Ionic Compounds with Transition Metals
Write the formula for Iron (III) Oxide.
First: What is the cation?
Second: What is the anion? 3+ 2- Fe O
Fe2O3

40. CuS
K3N
NaI
K2S
CaI2

41. What is a polyatomic ion?
Tightly bound groups of atoms that behave as a unit and carry a charge

42. Polyatomic Ions behave as a UNIT.
You CANNOT change the charge or the number of atoms of each element in a polyatomic ion or you will change the identity of that ion!!
ClO – Hypochlorite
ClO2 – Chlorite
ClO3 – Chlorate
ClO4 – Perchlorate

43. Naming Compounds with Polyatomic Ions
To name a compound containing a polyatomic ion, state the cation first, and then the anion.
Just like naming binary ionic compounds!
Except you DO NOT change the anion name!

44. Naming Compounds with Polyatomic Ions Example
CaSO4
What’s special about the anion?
SO4 is a polyatomic ion.
What is the name of the cation?
What is the name of the anion?
Calcium
Sulfate

45. Naming Compounds with Polyatomic Ions Example
AlPO4
What is the name of the cation?
What is the name of the anion?
Aluminum
Phosphate

46. Naming Compounds with Polyatomic Ions Example
NaCH3COO
What is the name of the cation?
What is the name of the anion?
Sodium
Acetate

47. Be aware – you can’t forget about your transition metals!
CuSiO3
SiO32- is
called silicate
What is the name of the cation?
What is the name of the anion?
Copper (II)
Silicate

48. Writing the Formula of a Compound Containing a Polyatomic Ion
Remember: Polyatomic ions behave as a unit.
You cannot change the assigned subscript.
Write the symbol for the cation, followed by the formula for the polyatomic ion, then balance the charges. Use parentheses.

49. Writing Formulas w/ Polyatomic Ions Example
Write the formula for Aluminum Chromate. 2- 3+
CrO4 Al
Al2(CrO4)3

50. Writing Formulas w/ Polyatomic Ions Example
Write the formula for Ammonium Sulfide. 2- +
NH4 S
(NH4)2S

51. Writing Formulas w/ Polyatomic Ions Example
Write the formula for Ammonium Sulfate. 2- +
SO4
NH4
(NH4)2SO4

52. Remember – there can still be compounds with transition metals!
Write the formula for Tin (II) Cyanide. - 2+ CN Sn
Sn(CN)2

53. Mg(OH)2
K2SO4

54. Ionic Name cation (name stays same) Name anion (ending in –ide)
That is a representative metal or transition metal with only 1 charge
Name cation
(name stays same)
Name anion
(ending in –ide)
Name cation
(use roman numerals)
Name anion
(ending in –ide)
That is a transition metal with multiple possible charges
Name cation
(see above)
Name anion
(polyatomic name)
Bonded to a polyatomic ion

55. Tin (IV) sulfide Magnesium nitrate Calcium bromide Sodium hydroxide
Try It!
Write the formulas of the following binary ionic compounds:
Tin (IV) sulfide
Magnesium nitrate
Calcium bromide
Sodium hydroxide
SnS2
Mg(NO3)2
CaBr2
NaOH

56. Quick Quiz
Section 9.2

57. 1. The correct name for CrCl3 is
chromium chlorine.
chromium(III) chloride.
monochromium trichloride.
chromium(III) trichloride.

58. 2. What is the correct formula for strontium nitride?
Sr3N2
SrN2
Sr2N3
Sr3N

59. 3. Which one of the following compounds is named correctly?
sodium chlorite, NaClO
potassium nitrate, KNO3
sodium acetate, Na2C2H3O2
lithium sulfate, Li2SO3

60. What’s Next?
Book Work
Page 258 (#8-9)
Page 266 (#17-19)

61. Page 258 #8 and Page 266 #17-19
Write the symbol for the ion of each element. Classify the ion as an anion or cation, and name the ion.
Write the formulas of the following compounds:
Beryllium Chloride
Cesium Sulfide
Potassium
Sodium Iodide
Oxygen
Strontium Oxide
Tin (2 electrons lost)
Write the formulas of these polyatomic compounds:
Bromine
Beryllium
Chromium (III) nitrate
Cobalt (3 electrons lost)
Sodium perchlorate
Write the symbol or formula (including charge) for each of the following ions.
Magnesium hydrogen carbonate
Calcium acetate
Identify any incorrect formulas and explain your reasoning.
Ammonium ion
Tin (II) ion
Mg2(SO4)3
Chromate ion
Rb3As
Nitrate ion
BeCl3
NaF

62. #8 – Write the symbol for the ion of each element
#8 – Write the symbol for the ion of each element. Classify the ion as an anion or cation, and name the ion.
Potassium  K+, cation, Potassium
Oxygen  O2-, anion, Oxide
Tin (2 electrons lost)  Sn2+, cation, Tin (II)
Bromine  Br-, anion, Bromide
Beryllium  Be2+, cation, Beryllium
Cobalt (3 electrons lost)  Co3+, cation, Cobalt (III)

63. Ammonium ion  NH4+ Tin (II) ion  Sn2+ Chromate ion  CrO42-
#9 – Write the symbol or formula (including charge) for each of the following ions.
Ammonium ion  NH4+
Tin (II) ion  Sn2+
Chromate ion  CrO42-
Nitrate ion NO3-

64. #17 – Write the formula for these binary compounds.
Beryllium Chloride
Cesium Sulfide
Sodium Iodide
Strontium Oxide
BeCl2
Cs2S
NaI
SrO

65. #18 – Write the formula these compounds containing polyatomic ions.
Chromium (III) nitrate
Sodium Perchlorate
Magnesium hydrogen carbonate
Calcium acetate
Cr(NO3)3
NaClO4
Mg(HCO3)2
Ca(C2H3O2)2 or Ca(CH3COO)2

66. #19 – Identify any incorrect formulas. Explain your answer.
Mg2(SO4)3
Rb3As
BeCl3
NaF
Should be MgSO4
Should be BeCl2

67. Section 9.3: Naming and Writing Formulas for Molecular Compounds
Read pages

68. Binary Molecular Compounds
A binary molecular compound is composed of two elements – both are nonmetals
Binary molecular compounds do not contain ions – they are made of…
molecules
Don’t use ionic charges to name or write formulas

69. Carbon and oxygen combine to form carbon monoxide (CO) and carbon dioxide (CO2), but these two invisible gases are very different. Sitting in a room with small amounts of CO2 in the air would not present any problems. If the same amount of CO were in the room, you could die of asphyxiation. A naming system that distinguishes between these two compounds is needed.

70. Naming Binary Molecular Compounds
Use prefixes
The prefix in the name of a binary molecular compound tells how many atoms of each element are present in each molecule of the compound

71. Steps for Naming a Binary Molecular Compound
Confirm that the compound is a binary molecular compound.
Name the elements in the order that they appear in the formula
Use prefixes to indicate the number of each kind of atom.
The name of the first element stays the same. The ending of the second element changes to –ide.

72. Quick Example – Add it to your notes!
S2Br4 di
sulfur
tetra
bromide

73. Special Rules
If there is only one atom of the first element in the formula, drop the mono-
If the element begins with a vowel, drop the vowel on the end of the prefix.
CCl4 is called carbon tetrachloride, NOT monocarbon tetrachloride.
Exceptions: Di- and Tri-
CO is called carbon monoxide, NOT carbon monooxide.

74. Naming Binary Molecular Compounds Example 1
N2O di
nitrogen
mon
oxide

75. Naming Binary Molecular Compounds Example 2
Cl2O8 di
chlorine
oct
oxide

76. CBr4 N2H4 PCl5 S2F10 Try It! Carbon tetrabromide
Write the names of the following binary molecular compounds:
CBr4
N2H4
PCl5
S2F10
Carbon tetrabromide
Dinitrogen tetrahydride
Phosphorus pentachloride
Disulfur decafluoride

77. Writing Formulas for Binary Molecular Compounds
Use the prefixes in the name to tell you the subscript of each element in the formula. Then, write the correct symbols for the two elements with the appropriate subscripts.

78. Writing Formulas for Binary Molecular Compounds Example 1
Dinitrogen trioxide N O 2 3

79. Writing Formulas for Binary Molecular Compounds Example 2
Iodine heptafluoride I F 7

80. Try it! CS2 Br3O8 SiC H2O Carbon disulfide Tribromine octoxide
Silicon monocarbide
Dihydrogen monoxide

81. Ionic Covalent Name compound using prefixes Name cation
Second element ends in -ide
That is a representative metal or transition metal with only 1 charge
Name cation
(name stays same)
Name anion
(ending in –ide)
That is a transition metal with multiple possible charges
Name cation
(use roman numerals)
Name anion
(ending in –ide)
Name cation
(see above)
Name anion
(polyatomic name)
Bonded to a polyatomic ion

82. Quick Quiz
Section 9.3

83. 1. Which of the following compounds is named INCORRECTLY?
CS2, carbon disulfide
BCl3, boron trichloride
IF7, iodine heptafluoride
PCl5, phosphorus hexachloride

84. 2. Which of the following molecular compounds is named INCORRECTLY?
SbCl3, antimony trichloride
C2O5, dicarbon pentoxide
CF4, carbon tetrafluoride
H3S, hydrogen sulfide

85. 3. The correct formula for tetraphosphorus trisulfide is
P3S4
S3P4
P4S3
S4P3

86. Section 9.4: Naming and Writing Formulas for Acids and Bases
Read pages

87. Naming Acids
Acid - a compound that contains one or more hydrogen atoms and produces hydrogen ions (H+) when dissolved in water
Hydrogen is most commonly listed first in the compound
Formula: HnX
NOTE: Acids do not have to have hydrogen first, but usually do.

88. Dependent on the anion (the non hydrogen part)
Rules for Naming Acids
Three rules
Dependent on the anion (the non hydrogen part)

89. Rule #1
When the name of the anion ends in –ide, the acid name begins with hydro-. The stem of the anion has the suffix –ic and is followed by acid.
Simply – if there is no oxygen in the acid formula, the formula for the name is hydro-root-ic acid.
Example
HCl
Cation – Hydrogen
Anion – Chloride
Name of Acid – Hydrochloric Acid

90. Rule #2
When the anion name ends in –ite, the acid name is the stem of the anion with the suffix –ous followed by the word acid.
Formula for name: Root-ous acid
Example
HClO2
Cation – Hydrogen
Anion – Chlorite
Name of Acid – Chlorous acid

91. Rule #3
When the anion name ends in –ate, the acid name is the stem of the anion with the suffix –ic followed by the word acid.
Formula for name: Root-ic acid
Example
HClO3
Cation – Hydrogen
Anion – Chlorate
Name of Acid – Chloric acid

92. Weird Roots Sulfur and Phosphorus Sulfur  Sulfuric, Sulfurous
Phosphorus  Phosphoric, Phosphorous

93. Practice Problems PO33- is phosphite Name the following acids: H2SO3
Sulfurous Acid
HNO3
Nitric Acid
HBr
Hydrobromic Acid
H3PO3
Phosphorous Acid
PO33- is phosphite

94. Writing Formulas for Acids
Use the rules in reverse
Example:
Write the formula for hydrocyanic acid.
Hydro-root-ic acid means the anion ends in –ide.
The cation is Hydrogen (H+).
The anion is Cyanide (CN-).
The formula for the acid is HCN.

95. Practice Problems CO22- is carbonite
Write the formulas for the following acids:
Hydroiodic acid HI
Carbonic acid
H2CO3
Carbonous acid
H2CO2
Acetic acid
HC2H3O2
CO22- is carbonite

96. Names and Formulas of Bases
Base – a compound that produces hydroxide ions (OH-) when dissolved in water
Named the same way as an ionic compound: Name of cation, then name of anion.
Anion is usually hydroxide (OH-) but it does not have to be.
Example:
NaOH
Cation: Sodium
Anion: Hydroxide
Name of Base: Sodium Hydroxide

97. Try it!
Provide the appropriate name or formula of the following bases:
Potassium hydroxide
KOH
Be(OH)2
Beryllium Hydroxide
RbOH
Rubidium Hydroxide
Aluminum hydroxide
Al(OH)3

98. This is an example of a base that does NOT contain a hydroxide ion.
A base to take note of:
NH3 is ammonia.
This is an example of a base that does NOT contain a hydroxide ion.

99. Weird Roots Sulfur and Phosphorus Sulfur  Sulfuric, Sulfurous
Phosphorus  Phosphoric, Phosphorous

100. Ionic Acid Covalent Name compound using prefixes Name cation
That is a representative metal or transition metal with only 1 charge
Name compound using prefixes
(second element ends in –ide)
Name cation
(name stays same)
Name anion
(ending in –ide)
Does not contain any oxygen
(Anion ends in –ide)
That is a transition metal with multiple possible charges
Name cation
(use roman numerals)
Name anion
(ending in –ide)
Hydro(root)ic acid
Name cation
(see above)
Name anion
(polyatomic name)
Bonded to a polyatomic ion
Anion ends in -ite
(Root)ous acid
If the anion is hydroxide (OH-) then you have a base
Anion ends in -ate
(Root)ic acid

101. Molecular Naming Review
CO2 CO
PBr5
P2O5
ICl3
N2O
NI3
SO2
N2O3
CBr4
Dinitrogen tetroxide
Sulfur trioxide
Nitrogen monoxide
Nitrogen dioxide
Diarsenic pentoxide
Phosphorus trichloride
Carbon tetrachloride
Dihydrogen monoxide
Selenium hexafluoride

102. Acid/Base Naming Review
Sodium hydroxide
Sulfurous acid
Hydrosulfuric acid
Phosphoric acid
Ammonia
Hydrocyanic acid
Calcium hydroxide
Iron (III) hydroxide
Hydrophosphoric acid HF
H2S
H2CO3
LiOH
HNO2
Co(OH)2
H2SO4
Be(OH) 2
HBr

103. Quick Quiz
Section 9.4

104. 1. An acid is a compound that produces WHAT when dissolved in water?
Hydroxide ions
Hydrogen ions
Polyatomic ions
Molecules

105. 2. Which of the following formulas is correct for the base: Calcium Hydroxide
CaOH2
CaH
CaOH
Ca(OH)2

106. What’s Next?
Practice Problems

107. Write the names of the following compounds:
The name a student gives for the molecular compound SiCl4 is monosilicon trichloride. Is this name correct? Explain.
NCl3
BCl3
Nl3
Write the formulas or names of the following compounds:
CS2
Carbon tetrabromide
Cl2O7
Diphosphorus trioxide
Write the molecular formulas of the following compounds:
Phosphorus pentachloride
Iodine heptafluoride
Chlorine trifluoride
Iodine dioxide
SO3
N2H4
N2O3
Name the following acids:
HNO2
HMnO4
HCN
H2S
Name the following bases:
LiOH
Pb(OH)2
Mg(OH)2
Al(OH)3
Write formulas for each of the following acids and bases:
Carbonic acid
Sulfurous acid
Iron (III) hydroxide
Strontium hydroxide

108. #22 – Write the names for these molecular compounds.
NCl3
BCl3
Nl3
SO3
N2H4
N2O3
Nitrogen trichloride
Boron trichloride
Nitrogen triodide
Sulfur trioxide
Dinitrogen tetrahydride
Dinitrogen trioxide

109. #23 – Write the formulas or names for these molecular compounds.
CS2
Carbon tetrabromide
Cl2O7
Diphosphorus trioxide
Carbon disulfide
CBr4
Dichlorine heptoxide
P2O3

110. #24 – Write the formulas for these binary molecular compounds.
Phosphorus pentachloride
Iodine heptafluoride
Chlorine trifluoride
Iodine dioxide
PCl5
IF7
ClF3
IO2

111. Silicon tetrachloride
#25 – The name a student gives for the molecular compound SiCl4 is monosilicon trichloride. Is this name correct? Explain.
Silicon tetrachloride

112. #29 – Give the names of these acids.
Nitrous acid
Permanganic acid
Hydrocyanic acid
Hydrosulfuric acid
HNO2
HMnO4
HCN
H2S

113. #30 – Write the names of these bases.
LiOH
Pb(OH)2
Mg(OH)2
Al(OH)3
Lithium hydroxide
Lead (II) hydroxide
Magnesium hydroxide
Aluminum hydroxide

114. #32 – Write the formulas of the following acids and bases:
Carbonic acid
Sulfurous acid
Iron (III) hydroxide
Strontium hydroxide
H2CO3
H2SO3
Fe(OH)3
Sr(OH)2

115. Section 9.5: The Laws Governing Formulas and Names
Read pages

116. The Laws Governing Formulas and Names
The rules for naming and writing formulas are possible because elements form compounds in predictable ways.
Two Important Laws
The Law of Definite Proportions
The Law of Multiple Proportions

117. The Law of Definite Proportions
States that in samples of any chemical compound, the masses of the elements are always in the same proportions.
So what does that mean?

118. Law of Definite Proportions Continued
Water
What is the formula for water? H2O
What is the atomic mass of Oxygen?
16.00
What is the atomic mass of Hydrogen?
1.00
What is the mass ratio of Oxygen to Hydrogen in water?
16:2 which reduces to 8:1
Hydrogen Peroxide
Dihydrogen Dioxide
What is the formula for hydrogen peroxide?
H2O2
What is the mass ratio of Oxygen to Hydrogen in water?
32:2 which reduces to 16:1
Regardless of how much you have, the ratio of masses is always the same!

119. Both water and hydrogen peroxide are composed of hydrogen and oxygen…
Both water and hydrogen peroxide are composed of hydrogen and oxygen…. But they have different properties.

120. Law of Multiple Proportions
Whenever the same two elements form more than one compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers.
Two Compounds
(X and Y) contain equal masses of Element B. The ratio of the masses of Element A in these compounds is 5:10 or 1:2.

121. Main Idea:
In any chemical compound, the elements are always in the same proportion by MASS.

122. Guidelines for Writing the Chemical Formula of a Compound
An –ide ending generally indicates a binary compound.
An –ite or –ate ending means a polyatomic ion that contains oxygen is in the formula.
Prefixes in a name generally indicate that the compound is molecular.
A Roman numeral after the name of a cation shows the charge of the cation.

123. Naming Review H in front of the formula? It’s an acid!
OH in the formula? It’s a base! (Ionic name)
Metal present? It’s ionic!
Check to see if you have a transition metal with multiple charges.
Only nonmetals? It’s covalent!

124. Dinitrogen tetrahydride
Naming Practice
Formula
Name
Ionic or Molecular?
Sodium chloride
BrF3
LiNO3
Dinitrogen tetrahydride
Potassium hydroxide
Rb2O
Hydrofluoric acid

125. Naming Practice Answers
Formula
Name
Ionic or Molecular?
NaCl
Sodium chloride
Ionic
BrF3
Bromine trifluoride
Molecular
LiNO3
Lithium nitrate
N2H4
Dinitrogen tetrahydride
KOH
Potassium hydroxide
Rb2O
Rubidium oxide HF
Hydrofluoric acid

126. What’s Next?
Book Work
Page 279 (#35, 39-41)

127. #35 – What two laws describe how chemical compounds form?
The Law of Definite Proportions
The Law of Multiple Proportions

128. #39 – Name these compounds:
CaCO3
PbCrO4
SnCr2O7
Calcium carbonate
Lead (II) chromate
Tin (II) dichromate

129. #40 – Write the formulas for these compounds:
Tin (II) hydroxide
Barium Fluoride
Sn(OH)2
BaF2

130. #40 – Identify the incorrect names or formulas.
Calcium (II) oxide
Aluminum oxide
Na2C2O4
Mg(NH4)2