Classifying Materials

1
Classifying Materials

• Atomic elements elements whose particles are
  single atoms.
• Molecular elements elements whose particles are
  multi-atom molecules.
• Molecular compounds compounds whose particles
  are molecules made of only nonmetals.
• Ionic compounds compounds whose particles are
  cations and anions.

2
Molecular View of Elements and Compounds
3
Molecular Elements

• Certain elements occur as 2 atom molecules
• Rule of 7s
• there are 7 common diatomic elements
• find the element with atomic number 7, N
• make a figure 7 by going over to Group 7A, then
  down
• dont forget to include H2

VIIA
7
H2
N2 O2 F2
Cl2
Br2
I2
4
Ionic Compounds

• Ionic compounds form when metals combine with
  nonmetals.
• There are no individual molecules, instead there
  is a 3-dimensional array made up of formula
  units of cations and anions.
• metal atoms form cations, nonmetal atoms for
  anions
• Compounds must have no total charge, therefore we
  must balance the numbers of cations and anions in
  a compound to get 0 charge
• If Na is combined with S2-, you will need 2 Na
  ions for every S2- ion to balance the charges,
  therefore the formula must be Na2S

5
Molecular Compounds

• two or more nonmetals
• smallest unit is a molecule

6
Classify each of the following as either an
atomic element, molecular element, molecular
compound or ionic compound

• aluminum, Al
• aluminum chloride, AlCl3
• chlorine, Cl2
• acetone, C3H6O
• carbon monoxide, CO
• cobalt, Co

7
Classify each of the following as either an
atomic element, molecular element, molecular
compound or ionic compound

• aluminum, Al atomic element
• aluminum chloride, AlCl3 ionic compound
• chlorine, Cl2 molecular element
• acetone, C3H6O molecular compound
• carbon monoxide, CO molecular compound
• cobalt, Co atomic element

8
Metal Cations

• Type I
• metals whose ions can only have one possible
  charge
• IA, IIA, (Al, Ga, In)
• determine charge by position on the Periodic
  Table
• IA 1, IIA 2, (Al, Ga, In 3)
• Type II
• metals whose ions can have more than one possible
  charge
• determine charge by charge on anion

How do you know a metal cation is Type II?
Its not Type I !!!
9
Determine if the following metals are Type I or
Type II. If Type I, determine the charge on the
cation it forms.

• lithium, Li
• copper, Cu
• gallium, Ga
• tin, Sn
• strontium, Sr

10
Determine if the following metals are Type I or
Type II. If Type I, determine the charge on the
cation it forms.

• lithium, Li Type I 1
• copper, Cu Type II
• gallium, Ga Type I 3
• tin, Sn Type II
• strontium, Sr Type I 2

11
Type I Binary Ionic Compounds

• Contain a Metal Cation a Nonmetal Anion
• Common simple cations and anions are listed in
  Table 5.1
• The Metal is listed first in the formula name
• Name the metal cation first, name the nonmetal
  anion second.
• The cation name is the same as the metal name.
• The nonmetal anion is named by changing the
  ending on the nonmetal name to ide

12
Example Naming Binary Ionic, Type I Metal CsF

• 1. Identify Major Class
  
  Cs is a metal because it is on the
  left side of the Periodic Table
• F is a nonmetal because it is on the right side
  of the Periodic Table Ionic
• Identify the Subclass
• 2 elements Binary Ionic
• 3. Is the metal Type I or Type II?
• Cs is in Group IA Type I
• 4. Identify the cation and anion
• Cs Cs because it is in Group 1
• F F- because it is in Group 7
• Name the cation
• Cs cesium
• 6. Name the anion
• F- fluoride
• 7. Write the cation name first, then the anion
  name
• cesium fluoride

13
Type II Binary Ionic Compounds

• Contain a Metal Cation a Nonmetal Anion
• Metal ions are listed first in the formula name
• Name the metal cation first, name the nonmetal
  anion second.
• Metal cation names are the metal name followed by
  a Roman Numeral in parentheses to indicate the
  charge on the cation.
• determine charge from the anion charge
• Common Type II cations (elements that have more
  than one possible charge) are listed in Table 5.2
• Nonmetal anions are named by changing the ending
  on the nonmetal name to -ide

14
Example Naming Binary Ionic, Type II MetalCuCl

• 1. Identify Major Class
• Cu is a metal because it is on the left side of
  the PT
• Cl is a nonmetal because it is on the right
  side of the PT
• ? Ionic
• Identify the Subclass
• 2 elements, ? Binary Ionic
• 3. Is the metal Type I or Type II
• Cu is not in Group IA, IIA, or (Al, Ga, In) ?
  Type II
• 4. Identify cation and anion
• Cl Cl- because it is Group 7
• Cu Cu to balance the charge
• Name the cation
• Cu copper(I)
• 6. Name the anion
• Cl- chloride
• 7. Write the cation name first, then the anion
  name
• copper(I) chloride

15
Determining the Charge on a Multivalent Cation
Au2S3

• determine the charge on the anion
• Au2S3 - the anion is S, since it is in Group 6A,
  its charge is -2
• determine the total negative charge
• since there are 3 S in the formula, the total
  negative charge is -6
• determine the total positive charge
• since the total negative charge is -6, the total
  positive charge is 6
• divide by the number of cations
• since there are 2 Au in the formula the total
  positive charge is 6, each Au has a 3 charge

16
Examples Name the following

• LiCl
• AlCl3
• PbO
• PbO2
• Mn2O3
• ZnCl2
• AgCl

17
Examples

• LiCl lithium chloride
• AlCl3 aluminum chloride
• PbO lead(II) oxide
• PbO2 lead(IV) oxide
• Mn2O3 manganese(III) oxide
• ZnCl2 zinc(II) chloride or zinc chloride
• AgCl silver(I) chloride or silver chloride

18
Naming Type III Binary Molecular Compounds of 2
Nonmetals

• Name the first element in the formula first
• use the full name of the element
• Name the second element in the formula with an
  -ide
• as if it were an anion, however, remember these
  compounds do not contain ions!
• Use a prefix in front of each name to indicate
  the number of atoms
• Never use the prefix mono- on the first element

19
Subscript - Prefixes

• 1 mono-
• not used on first nonmetal
• 2 di-
• 3 tri-
• 4 tetra-
• 5 penta-
• 6 hexa-
• 7 hepta-
• 8 octa-
• drop the last a if the name begins with a vowel
• Remember these prefixes listed in Table 5.3

20
Example Naming Binary MolecularBF3

• 1. Identify Major Class
• B is a nonmetal because it is on the right side
  of the PT
• F is a nonmetal because it is on the right side
  of the PT
• ? Molecular
• Identify the Subclass
• 2 elements ? Binary Molecular
• Name the first element
• boron
• Name the second element with an ide
• fluorine ? fluoride
• Add a prefix to each name to indicate the
  subscript
• monoboron, trifluoride
• Write the first element with prefix, then the
  second element with prefix
• Drop prefix mono from first element
• boron trifluoride

21
Compounds Containing Polyatomic Ions

• Polyatomic ions are single ions that contain more
  than one atom.
• Name these compounds using procedures similar to
  those for naming binary ionic compounds.
• Use Table 5.4 to help you recognize these ions
  until you have memorized them.
• Note that several polyatomic anions exist that
  contain an atom of a given element and different
  numbers of oxygen atoms. These anions are called
  oxyanions. E.g. oxyanions containing chlorine
  are
• ClO- hypochlorite
• ClO2- chlorite
• ClO3- chlorate
• ClO4- perchlorate

22
Some Common Polyatomic Ions
Name Formula
acetate C2H3O2
carbonate CO32
hydrogen carbonate (bicarbonate) HCO3
hydroxide OH
nitrate NO3
nitrite NO2
chromate CrO42
dichromate Cr2O72
ammonium NH4
Name Formula
hypochlorite ClO
chlorite ClO2
chlorate ClO3
perchlorate ClO4
sulfate SO42
sulfite SO32
Hydrogen sulfate (bisulfate) HSO4
Hydrogen sulfite (bisulfite) HSO3
23
Molecules with Polyatomic Ions
Mg(NO3)2 compound called magnesium nitrate
CaSO4 compound called calcium sulfate
24
Molecules with Polyatomic Ions
Mg(NO3)2 compound called magnesium nitrate
CaSO4 compound called calcium sulfate
25
Example Naming Ionic Substances when there is a
Polyatomic Ion Na2SO4

• Identify Major Class Na is a metal because it is
  on the left side of the PT
  SO42- is a polyatomic ion ? Ionic
• Identify the Subclass compound has 3 elements
  ? Ionic with a Polyatomic Ion
• 3. Is the metal Type I or Type II? Na is in
  Group IA Type I
• Identify the ions Na Na because it is in
  Group 1 SO42- SO42- is a polyatomic ion
• Name the cation Na sodium ion (Type I)
• 6. Name the anion SO42- sulfate ion
• 7. Write the name of the cation followed by the
  name of the anion
• sodium sulfate

26
Example Naming Ionic substances with Polyatomic
Ion Fe(NO3)3

• 1. Identify Major Class Fe is a metal
  because it is on the left side of the
  Periodic Table
• NO31- is a polyatomic ion Ionic
• Identify the Subclass there are 3 elements ?
  Ionic with a Polyatomic Ion
• Is the metal Type I or Type II? Fe is not in
  Group IA, IIA, or (Al, Ga, In) ? Type II
• 4. Identify the ions NO3 NO3- is a polyatomic
  ion
• Fe Fe3 to balance the charge of the 3
  NO3-1
• Name the cation Fe3 iron(III) ion (Type II)
• 6. Name the anion NO3- nitrate ion
• 7. Write the name of the cation followed by the
  name of the anion
• iron(III) nitrate

27
Additional Examples

• Name the following compounds
• PbCO3
• Ca(HCO3)2
• Fe(OH)2
• Cu(NO3)2
• NH4I
• KHSO4

28
Additional Examples

• Name the following compounds
• PbCO3 lead(II) carbonate
• Ca(HCO3)2 calcium hydrogen carbonate
• Fe(OH)2 iron(II) hydroxide
• Cu(NO3)2 copper(II) nitrate
• NH4I ammonium iodide
• KHSO4 potassium hydrogen sulfate

29
Naming Acids

• Contain H3O1 cation and an anion in an aqueous
  solution
• Binary acids have H3O1 cation and a nonmetal
  anion
• Oxyacids have H3O1 cation and a polyatomic anion
• Acids are molecular compounds that often behave
  like they are made of ions
• All names have acid at the end
• Binary Acids hydro prefix stem of the name of
  the nonmetal ic suffix See Table 5.5
• Oxyacids See Table 5.6
• if the polyatomic ion ends in ate name the
  polyatomic ion with an ic suffix
• if the polyatomic ion ends in ite name the
  polyatomic ion with an ous suffix

30
Example Naming Binary AcidsHCl

• Identify Major Class first element listed is H,
  ? Acid
• Identify the Subclass 2 elements, ? Binary Acid
• Identify the anion Cl Cl-, chloride because
  it is in Group 7A
• Name the anion with an ic suffix Cl-
  chloride ? chloric
• Add a hydro- prefix to the anion name
  hydrochloric
• Add the word acid to the end hydrochloric acid

31
Example Naming OxyacidsH2SO4

• Identify Major Class first element listed is
  H, ? Acid
• Identify the Subclass 3 elements in the
  formula, ? Oxyacid
• 3. Identify the anion SO4 SO42- sulfate
• If the anion has ate suffix, change it to ic.
  If the anion has ite suffix, change it to ous
  SO42- sulfate ? sulfuric
• Write the name of the anion followed by the word
  acid
• sulfuric acid

32
Example Naming Oxyacids H2SO3

• Identify Major Class first element listed is
  H, ? Acid
• Identify the Subclass 3 elements in the
  formula, ? Oxyacid
• Identify the anion SO3 SO32- sulfite
• If the anion has ate suffix, change it to ic.
  If the anion has ite suffix, change it to ous
  SO32- sulfite ? sulfurous
• Write the name of the anion followed by the word
  acid
• sulfurous acid

33
Additional Examples

• Name the following acids
• HF
• H3PO3
• HNO3
• HBrO4
• H2S

34
Additional Examples

• Name the following acids
• HF hydrofluoric acid
• H3PO3 phosphorous acid
• HNO3 nitric acid
• HBrO4 perbromic acid
• H2S hydrosulfuric acid

35
Formula-to-Name Flow Chart
36
Formula-to-NameStep 1
Is the compound one of the exceptions to the
rules?
37
Common Names - Exceptions

• H2O water, steam, ice
• NH3 ammonia
• CH4 methane
• NaCl table salt
• C12H22O11 table sugar

38
Formula-to-NameStep 2
What major class of compound is it? Ionic or
Molecular
39
Major Classes

• Ionic
• metal nonmetal
• The metal is written first in the formula
• Binary Ionic
• compounds with polyatomic ions
• Molecular
• 2 nonmetals
• Binary Molecular (or Binary Covalent)
• Acids formula starts with H
• although acids are molecular, they behave as
  ionic substances when dissolved in water
• They may be binary or an oxyacid

40
Formula-to-NameStep 3
What major subclass of compound is it? Binary
Ionic, Ionic with Polyatomic Ions, Binary
Molecular, Binary Acid, Oxyacid
41
Classifying Compounds into major subclasses

• Compounds containing a metal and a nonmetal
  binary ionic
• Type I and II
• Compounds containing two nonmetals binary
  molecular compounds Type III
• Compounds containing a polyatomic ion ionic
  with polyatomic ion
• Compounds containing H and a nonmetal binary
  acids
• Compounds containing H and a polyatomic ion
  oxyacids

42
Formula-to-NameStep 4
Apply Rules for the Class and Subclass
43
Formula-to-NameRules for Ionic

• Made of cations and anions
• Name by simply naming the ions
• If the cation is
• Type I metal metal name
• Type II metal metal name with the charge
  written in parentheses as a Roman Numeral
• Polyatomic ion name of polyatomic ion
• If the anion is
• Nonmetal stem of nonmetal name ide
• Polyatomic ion name of polyatomic ion

44
Monatomic Nonmetal Anion

• determine the charge from the position on the
  Periodic Table
• to name the anion, change the ending on the
  element name to ide

4A -4 5A -3 6A -2 7A -1
C carbide N nitride O oxide F fluoride
Si silicide P phosphide S sulfide Cl chloride
45
Periodic Pattern of Polyatomic Ions-ate groups
IIIA IVA VA VIA
VIIA
46
Patterns for Polyatomic Ions

• -ate ion
• chlorate ClO3-1
• -ate ion 1 O ? same charge, per- prefix
• perchlorate ClO4-1
• \
• -ate ion 1 O ? same charge, -ite suffix
• chlorite ClO2-1
• -ate ion 2 O ? same charge, hypo- prefix, -ite
  suffix
• hypochlorite ClO-1

47
Practice - What are the formulas for compounds
made from the following ions?

• copper(II) ion with a nitride ion
• iron(III) ion with a bromide ion
• aluminum ion with a sulfate ion

48

• Cu2 with N3- Cu3N2
• Fe3 with Br- FeBr3
• Al3 with SO42- Al2(SO4)3

49
Formulas Describe Compounds

• A compound is a distinct substance that is
  composed of atoms of two or more elements.
• Formulas describe a compound by showing the
  number and type of each atom in the simplest unit
  of the compound
• molecules or ions H2O, NaCl
• Each element in a compound formula is represented
  by the chemical symbol that identifies the
  element NaCl, sodium chloride
• The number of atoms of each element is written to
  the right of the element as a subscript
• if there is only one atom, the 1 subscript is not
  written and is understood CO, carbon monoxide
  CO2, carbon dioxide
• polyatomic groups are placed in parentheses
• if more than one group is part of the formula the
  number of groups is written as a subscript

50
Formulas Describe Compounds
Water H2O two atoms of hydrogen and 1 atom
of oxygen Table sugar C12H22O11 12 atoms of
C, 22 atoms of H and 11 atoms of O
51
Writing the Formulas from the Names

• For binary molecular compounds, use the prefixes
  to determine the subscripts
• For Type I, Type II, Ternary Compounds and Acids
• Determine the ions present
• Determine the charges on the cation and anion
• Balance the charges to get the subscripts

52
Example Binary Moleculardinitrogen pentoxide

• Identify the symbols of the elements
• nitrogen N
• oxide oxygen O
• Write the formula using the prefix number for
  the subscript
• di 2, penta 5
• N2O5

53
Example Ionic Compoundsmanganese(IV) sulfide

1. Write the symbol for the cation and its charge
2. Write the symbol for the anion and its charge
3. Charge (without sign) becomes subscript for other
   ion
4. Reduce subscripts to smallest whole number ratio
5. Check that the total charge of the cations
   cancels the total charge of the anions

Mn4
S2-
Mn2S4
Mn4 S2-
MnS2
Mn (1)(4) 4 S (2)(-2) -4
54
Example Ionic CompoundsIron(III) phosphate

1. Write the symbol for the cation and its charge
2. Write the symbol for the anion and its charge
3. Charge (without sign) becomes subscript for other
   ion
4. Reduce subscripts to smallest whole number ratio
5. Check that the total charge of the cations
   cancels the total charge of the anions

Fe3
PO43-
Fe3 PO43-
Fe3(PO4)3
FePO4
Fe (1)(3) 3 PO4 (1)(-3) -3
55
Example Ionic Compoundsammonium carbonate
NH4

1. Write the symbol for the cation and its charge
2. Write the symbol for the anion and its charge
3. Charge (without sign) becomes subscript for other
   ion
4. Reduce subscripts to smallest whole number ratio
5. Check that the total charge of the cations
   cancels the total charge of the anions

CO32-
NH4 CO32-
(NH4)2CO3
(NH4)2CO3
NH4 (2)(1) 2 CO3 (1)(-2) -2
56
Example Binary Acidshydrosulfuric acid
in all acids the cation is H
H

1. Write the symbol for the cation and its charge
2. Write the symbol for the anion and its charge
3. Charge (without sign) becomes subscript for other
   ion
4. Reduce subscripts to smallest whole number ratio
5. Check that the total charge of the cations
   cancels the total charge of the anions

hydro means binary
S2-
H S2-
H2S
H2S
H (2)(1) 2 S (1)(-2) -2
57
Example Oxyacidscarbonic acid
in all acids the cation is H
H

1. Write the symbol for the cation and its charge
2. Write the symbol for the anion and its charge
3. Charge (without sign) becomes subscript for other
   ion
4. Reduce subscripts to smallest whole number ratio
5. Check that the total charge of the cations
   cancels the total charge of the anions

no hydro means polyatomic ion
CO32-
-ic means -ate ion
H CO32-
H2CO3
H2CO3
H (2)(1) 2 CO3 (1)(-2) -2
58
Practice - What are the formulas for the
following acids?

• chlorous acid
• phosphoric acid
• hydrobromic acid

59

• H with ClO2 HClO2
• H with PO43 H3PO4
• H with Br HBr