1. Chapter 9 Naming Ions

2. Monatomic Ions
Ionic compounds consists of a positive metal ion and a negative nonmetal ion combined in a proportion such that their charges add up to a net charge of zero.
NaCl – consists of one Na+ and one Cl-.
Monatomic ions consists of a single atom with a positive or negative charge resulting from the loss or gain of one or more valence electrons.

3. Monatomic Ions - Cations
Cations tend to lose valence electrons. (1+ charge – lose 1 electron, 2+ charge – lose 2 electrons, etc. )
When the metals in Groups 1A, 2A, and 3A lose electrons, they form cations with positive charges equal to their group number.
The name of the cations of the Group 1A, 2A and 3A are the same as the name of the metal, followed by the word ion or cation.
Na+ is sodium ion, Ca2+ is calcium ion, Al3+ is aluminum ion.

4. Monatomic Ions - Anions
Nonmetals tend to gain electrons for form anions, so the charge of a nonmetallic ion is negative.
The charge of any ion of a Group A nonmetal is determined by subtracting 9 from the group number.
Group 7A form anions with a 1- charge (7-8 = -1)
Anion names start with the stem of the element name and end in –ide.
Anion of fluorine is fluoride ion (F-), anion of chlorine is chloride ion (Cl-)

5. Ions of Transition Metals
Many of the transition metals (Group 1B – 8B) form more than one cation with different ionic charges.
Two methods are used to name these ions.
Stock System – a roman numeral in parentheses is placed after the name of the element to indicate the numerical value of the charge.
Fe2+ is iron(II) ions Fe3+ is iron(III) ion.
Classical – name of the element is used to form the root name for the element.
Fe2+ is ferrous ion Fe3+ is ferric ions

6. Ag1+
silver
Cd2+
cadmium
Zn2+
zinc
Au1+
gold(I) / aurous
Au3+
gold(III) / auric
Co2+
cobalt(II) / cobaltous
Co3+
cobalt(III) /cobaltic
Cr2+
chromium(II) / chromous
Cr3+
chromium(III) /chromic
Cu1+
copper(I) / cuprous
Cu2+
copper(II) /cupric
Fe2+
iron(II) / ferrous
Fe3+
iron(III) / ferric
Hg1+
mercury(I) / mercurous
Hg2+
mercury(II) / mercuric
Mn2+
manganese(II)
Mn3+
manganese(III)
Mn4+
manganese(IV)
Ni2+
nickel(II) / nickelous
Ni3+
nickel(III) / nickelic
Pb2+
lead(II) /plumbous
Pb4+
lead(IV) / plumbic

7. Polyatomic Ions Polyatomic Ions are composed of more than one atom.
Sulfate ions (SO42-) is composed of one sulfur atom and four oxygen atoms.
Polyatomic ions are a tightly bound group of atoms that behave as a unit and carry a charge.
The names of most polyatomic anions end in –ite or –ate.

8. +1 CHARGE
ion
name
NH4+
ammonium
H3O+
hydronium
Hg22+
mercury(I)
-1 CHARGE
ion
name
H2PO3-
dihydrogen phosphite
H2PO4-
dihydrogen phosphate
HCO3-
hydrogen carbonate
HSO3-
hydrogen sulfite
HSO4-
hydrogen sulfate
NO2-
nitrite
NO3-
nitrate
OH-
hydroxide
CH3COO-
acetate

9. -1 CHARGE
ion
name
CrO2-
chromite
CN-
cyanide
CNO-
cyanate
CNS-
thiocyanate
O2-
superoxide
MnO4-
permanganate
ClO-
hypochlorite
ClO2-
chlorite
ClO3-
chlorate
ClO4-
perchlorate
-1 CHARGE
ion
name
BrO-
hypobromite
BrO2-
bromite
BrO3-
bromate
BrO4-
perbromate
IO-
hypoiodite
IO2-
iodite
IO3-
iodate
IO4-
periodate
AlO2-
aluminate
N3-
azide

10. -2 CHARGE
ion
name
HPO32-
hydrogen phosphite
HPO42-
hydrogen phosphate
CO32-
carbonate
SO32-
sulfite
SO42-
sulfate
S2O32-
thiosulfate
SiO32-
silicate
-2 CHARGE
ion
name
C22-
carbide
C2O42-
oxalate
CrO42-
chromate
Cr2O72-
dichromate
C4H4O62-
tartrate
MoO42-
molybdate
O22-
peroxide
S22-
disulfide

11. -3 CHARGE
-4 CHARGE
ion
name
PO33-
phosphite
P2O74-
pyrophosphate
PO43-
phosphate
PO23-
hypophosphite
AsO33-
arsenite
AsO43-
arsenate

12. End of Section 9.1

13. Naming Binary Ionic Compounds
A binary compound is composed of two elements and can be either ionic or molecular (covalent)
To name any binary ionic compound, place the cation name first, followed by the anion name.
Cs2O is cesium oxide NaBr is sodium bromide
Cu2O is copper(I) oxide CuO is copper(II) oxide

14. Writing Formulas Binary Ionic Compounds
Write the symbol of the cation and then the anion. Add whatever subscripts 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 formula is zero.
K+ + Cl-  KCl
Ca2+ + Br-  CaBr2
Fe3+ + O2-  Fe2O3
Use the crisscross method – the numerical value of the charge of each ion is crossed over and becomes the subscript for the other ion.

15. Writing Formulas Polyatomic Ionic Compounds
An –ate or –ite ending on the name of a compound indicates that the compound contains a polyatomic anion that includes oxygen.
Write the symbol for the cation followed by the formula for the polyatomic ion and balance the charges.
Ca2+ + NO3-  Ca(NO3)2
Sr2+ + SO32-  SrSO3
Li+ + CO32-  Li2CO3
Use the crisscross method – the numerical value of the charge of each ion (polyatomic too) is crossed over and becomes the subscript for the other ion.

16. Naming Polyatomic Ionic Compounds
First recognize that the compound contains a polyatomic ion.
State the cation first and then the anion
NaClO
sodium hypochlorite
(NH4)2C2O4
ammonium oxalate
Li2CO3
lithium carbonate

17. End of Section 9.2

18. Naming Molecular Compounds
Binary ionic compounds are composed of the ions of two elements, a metal and a nonmetal.
Binary molecular compounds are composed of two elements, two nonmetals and they are not ions.
Binary molecular compounds are composed of molecules, not ions, so ionic charges cannot be used to write formulas or to name them.
In addition, when two nonmetallic elements combine, the often do so in more than one way. (CO, CO2)
Prefixes in the names of binary molecular compounds help distinguish compounds containing different amounts of the same two elements.

19. Naming Molecular Compounds
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.
Prefix
Number
mono- 1
di- 2
tri- 3
tetra- 4
penta- 5
hexa- 6
hepta- 7
octa- 8
nona- 9
deca- 10

20. Naming Molecular Compounds
The names of all binary molecular compounds end in –ide.
CO is carbon monoxide
CO2 is carbon dioxide
If just one atom of the first element is in the formula, omit the prefix mono-
Name the elements in order listed in the formula
Use prefixed to indicate the number of each kind of atom
The suffix of the name of the second element is –ide.
N2O is dinitrogen monoxide
SF6 is sulfur hexafluoride.

21. Writing Formulas 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.
Silicon Carbide
SiC
Dinitrogen tetraoxide
N2O4
Diphosphorus trioxide
P2O3

22. End of Section 9.3
End of Chapter 7

23. Naming Acids
Acid is a compound that contains one or more hydrogen atoms and produces hydrogen ions (H+) when dissolved in water.
When naming acids, the acid consists of an anion combined with as many hydrogen ions s are needed to make the molecule electrically neutral.
The general chemical formulas of acids is HnX.
X is a monatomic or polyatomic anion
n is a subscript indication the number of hydrogen ions combined with the anion.

24. Naming Acids
Three rules are used to name acids. The name depends on the name of the anion and its suffix (-ide, -ite, -ic)
a. When the name of the anion ends in –ide, the acid name begins with the prefix hydro-.
b. The stem of the anion has the suffix –ic and is followed by the word acid.
H Cl  HCl
Hydrogen ion chloride ion hydrochloric acid
H S  H2S
Hydrogen ion sulfide ion hydrosulfuric acid

25. Naming Acids
Three rules are used to name acids. The name depends on the name of the anion and its suffix (-ide, -ite, -ic)
a. 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
H SO  H2SO3
Hydrogen ion sulfite ion sulfurous acid
H IO  HIO2
Hydrogen ion iodite ion iodous acid

26. Naming Acids
Three rules are used to name acids. The name depends on the name of the anion and its suffix (-ide, -ite, -ic)
a. When the anion name end in –ate, the acid name is the stem of the anion with the suffix –ic followed by the word acid.
H NO  HNO3
Hydrogen ion nitrate ion nitric acid
H SO  H2SO4
Hydrogen ion sulfate ion sulfuric acid

27. Writing Formulas for Acids
Use the rules for writing the names of acids in reverse to write the formula for acids.
Hydrobromic acid
Hydro indicates the bromide ion
HBr
Phosphorous acid
-ous indicates the phosphite ion
H3PO3
Formic acid
-ic and beginning with the anion name indicates the formate ion
HCOOH

28. Bases
A base is an ionic compound that produced hydroxide ions (OH-)when dissolved in water.
Bases are named the same way as other ionic compounds – the name of the cation is followed by the name of the anion.
NaOH is sodium hydroxide
To write the formulas for bases, write the symbol for the cation followed by the formula for the hydroxide ion. (balance the ionic charges jusat as you do for any ionic compound)
Aluminum hydroxide – Al3+ + OH-  Al(OH)3
Ammonium hydroxide – NH4+ + OH-  NH4OH

29. End of Section 9.4
End of Chapter 7

30. Laws Governing Formulas & Names
Law of Definite Proportions
A chemical formula tells you (by subscripts) the ratio of atoms of each element in the compound.
Ratios of atoms can also be expressed as ratios of masses.
100 g of MgS breaks down into 43.12g Mg and 56.88g of sulfur.
100g MgS 1 mol MgS 1 mol Mg g Mg = 43.12g Mg
56.4g MgS 1 mol MgS 1 mol Mg
100g MgS 1 mol MgS 1 mol S g S = 56.88g S
56.4g MgS 1 mol MgS 1 mol S

31. Laws Governing Formulas & Names
The ratios of these masses is 43.12/56.88 = 0.758:1
The mass ratio of 0.758:1 does not change no matter how the magnesium sulfide is formed or the size of the sample.
Law of Definite proportions states that in samples of any chemical compound, the masses of the elements are always in the same proportions.
MgS illustrates the law of definite proportions

32. Laws Governing Formulas & Names
The Law of Multiple Proportions
Water (H2O) and hydrogen peroxide (H2O2) are formed by the same two elements, they have different physical and chemical properties.
Each compound obeys the law of definite proportions in every sample of hydrogen peroxide. (16g O : 1g H)
In every sample of water, the mass ratio of O to H is always 8:1 (8g O: 1g H)
If a sample of H2O2 has the same mass of H as a sample of H2O, the ratio of the mass of O in the two compounds is exactly 2:1

33. Laws Governing Formulas & Names
16 g O (in H2O2 has 1g H) = 16 = 2 = 2:1
8 g O (in H2O has 1 g H)
Law of multiple proportions states that 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.

34. End of Chapter 9