1. Chemical Formulas and Names
9.1 Naming Ions
9.2 Naming and Writing Formulas for Ionic Compounds
9.3 Naming and Writing Formulas for Molecular Compounds
9.4 Naming and Writing Compounds for Acids and Bases
9.5 The Laws Governing Formulas and Names
Updated 1/18/2019
Created by C. Ippolito June 2007 1

2. Created by C. Ippolito June 2007
Naming Ions
Objectives
Identify the charges of monatomic ions by using the periodic table, and name the ions.
Define a polyatomic ion and write the names and formulas of the most common polyatomic ions
Identify the two common endings for the names of most polyatomic ions
Updated 1/18/2019
Created by C. Ippolito June 2007 2

3. Created by C. Ippolito June 2007
Monoatomic Ions
Monoatomic Ions
consist of a single atom with a positive or negative charge resulting from the loss or gain of valence electrons
Cations – positive ions
Groups 1, 2, and 13
name is name of metal followed by “ion” or “cation”
Anions – negative ions
Groups 15, 16, and 17
name is stem of element name with ending “-ide” followed by “ion” or “anion”
Transition Metals – varying positive ions
Groups 3 through 12
name is name of metal with (Roman Numeral denoting charge) followed by “ion” or “cation”
Updated 1/18/2019
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4. Created by C. Ippolito June 2007
Polyatomic Ions
Polyatomic ions
composed of more than one atom but act as a single ion
most common endings are “-ate” and “-ite”
SO42- - sulfate and SO32- - sulfite
NO3- - nitrate and NO2- - nitrite
additional endings are “-ide” and “-ium”
NH4+ - ammonium
OH- - hydroxide and CN- - cyanide
hydrogen containing add name hydrogen
HCO3- - hydrogen carbonate
Updated 1/18/2019
Created by C. Ippolito June 2007 4

5. Naming and Writing Formulas for Ionic Compounds
Objectives
Apply the rules for naming and writing formulas for binary ionic compounds
Apply the rues for naming and writing formulas for compounds with polyatomic ions
Updated 1/18/2019
Created by C. Ippolito June 2007 5

6. Naming Binary Ionic Compounds
Place cation name first followed by anion name without the “ion”
NaBr – sodium bromide
SrF2 – strontium fluoride
CuO – copper(II) oxide
Cu2O – copper(I) oxide
Updated 1/18/2019
Created by C. Ippolito June 2007 6

7. Writing Formulas for Binary Ionic Compounds
Write symbol of the cation and then the anion adding subscripts needed to balance the charges (sum of charges = 0)
potassium chloride
K+ and Cl- - (+1)(-1) – 1:1 ratio – KCl
calcium bromide
Ca2+ and Br- - (+2)2(-1) – 1:2 ration CaBr2
Crisscross Method (Cross-over Rule)
Updated 1/18/2019
Created by C. Ippolito June 2007 7

8. Compounds with Polyatomic Ions
Write the symbol for the cation followed by the formula for the polyatomic ion and balance the charges
calcium nitrate
Ca2+ + NO3-1 – (+2)2(-1) – 1:2 ratio – Ca(NO3)2
Crisscross Method (Cross-over Rule)
Updated 1/18/2019
Created by C. Ippolito June 2007 8

9. Naming Compounds with Polyatomic Ions
State the cation first and then the anion same as naming binary ionic compounds
LiCN – lithium cyanide
NaClO – sodium hypochlorite
(NH4)2C2O4 – ammonium oxalate
Updated 1/18/2019
Created by C. Ippolito June 2007 9

10. Naming and Writing Formulas for Molecular Compounds
Objectives
Interpret the prefixes in the names of molecular compounds in terms of their chemical formulas
Apply the rues for naming and writing formulas for binary molecular compounds
Updated 1/18/2019
Created by C. Ippolito June 2007 10

11. Naming Binary Molecular Compounds
A prefix in the name tells how many atoms of an element are present in each molecule
all end in “-ide”
omit “mono-” prefix if for first element
CO – carbon monoxide
CO2 – carbon dioxide
N2O2 – dinitrogen dioxide
Cl2O8 – dichlorine octoxide
Updated 1/18/2019
Created by C. Ippolito June 2007 11

12. Writing Formulas for Binary Compounds
Use prefixes in the name to tell you the subscript of each element in the formula. Write the correct symbols for elements with appropriate subscripts
silicon carbide – SiC
dinitrogen tetroxide – N2O4
iodine dioxide – IO2
Updated 1/18/2019
Created by C. Ippolito June 2007 12

13. Naming and Writing Formulas for Acids and Bases
Objectives
Apply three rules for naming acids
Apply the rules in reverse to write formulas of acids
Apply the rules for naming bases
Updated 1/18/2019
Created by C. Ippolito June 2007 13

14. Created by C. Ippolito June 2007
Naming Acids
Acid – compound with one or more hydrogen atoms that produces hydrogen ions (H+) when dissolved in water
anion ends in “-ide” – name begins with “hydro-” and stem of anion with “-ic” followed by acid.
HCl(aq) – hydrochloric acid H2S(aq) – hydrosulfuric acid
anion ends in “-ite” – name is stem of anion with “-ous” followed by acid
H2SO3(aq) – sulfurous acid HNO2(aq) – nitrous acid
anion ends in “-ate” – name is stem of anion with “-ic” followed by acid
HNO3(aq) – nitric acid H2SO4(aq) – sulfuric acid
Updated 1/18/2019
Created by C. Ippolito June 2007 14

15. Writing Formulas for Acids
Use rules for writing names of acids in reverse to write formulas
Rule 1
hydrobromic acid – hydrogen ion and bromide ion
H+ and Br- - HBr(aq)
Rule 2
phosphorous acid – hydrogen ion and phosphite ion
H+ and PO33- - H3PO3(aq)
Rule 3
formic acid – hydrogen ion and formate ion
H+ and HCOO- - HCOOH(aq)
Updated 1/18/2019
Created by C. Ippolito June 2007 15

16. Names and Formulas for Bases
Base – ionic compound that produces hydroxide ions (OH-) when dissolved in water
Bases are named in the same way as other ionic compounds – the cation name followed by the name of the anion
sodium hydroxide – NaOH
aluminum hydroxide – Al(OH)3
calcium hydroxide – Ca(OH)2
Updated 1/18/2019
Created by C. Ippolito June 2007 16

17. The Laws Governing Formulas and Names
Objectives
Define the laws of definite proportions and multiple proportions
Apply the rules for naming chemical compounds by using a flowchart.
Apply the rules for writing the formulas of chemical compounds by using flow chart
Updated 1/18/2019
Created by C. Ippolito June 2007 17

18. The Law of Definite and Multiple Proportions
Law of Definite Proportions
In samples of any chemical compound, the masses of the elements are always in the same proportion
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 ration of small whole numbers
Updated 1/18/2019
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19. Calculating Mass Ratios
Updated 1/18/2019
Created by C. Ippolito June 2007 19

20. Calculating Mass Ratios
Updated 1/18/2019
Created by C. Ippolito June 2007 20

21. Calculating Mass Ratios
Updated 1/18/2019
Created by C. Ippolito June 2007 21