Ch 6: Bonding, Formulas and Naming Notes

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Ch 6 Bonding, Formulas and Naming Notes
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Bonding Objectives
Chem 5.0 Bonding, Formulas and Naming - OBJECTIVES










Describe Ionic Bonding Theory.
Describe Covalent Bonding Theory.
Write formulas and names for ionic compounds
including binary, tertiary and polyvalent.
Write formulas and names for molecules
(covalent compounds.)
Write formulas and names for hydrates.
Write formulas and names for binary and
tertiary acids.
Write Lewis-Dot structures for ionic compounds.
Write structural formulas for covalent
compounds.
Describe electronegativity and how it affects
bond type ionic, polar covalent and
nonpolar covalent.
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Types of Chemical Bonds

• A. Ionic Bonding
• 1) Positively charged ions are attracted to
  negatively
• charged ions, making a neutral compound.
• 2) Properties of Ionic Compounds
• a) high melting points.
• b) dissolve in water to form solutions
  that are good conductors of electricity
  (electrolytes).
• c) have a large electronegativity difference
• between elements.
• d) usually form between metals and nonmetals.

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3) The Octet Rule

• a) Atoms tend to gain or lose electrons in order
  to acquire a full set of valence electrons
  (stable octet).
• b) Atoms will transfer electrons (e-) to each
  other in order to have a full set of valence
  electrons.
• c) When electrons are transferred, ionic bonds
  are formed.

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4) Types of Compounds

• a) Binary form from monatomic ions have 1
  cation and 1 anion.
• Ex) Mg2 O-2
• Ca2 Cl-1

MgO
CaCl2
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Writing Ionic Formulas
This may not be on your notes, but if you dont
know how to do this it will severely affect your
grade
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• When chemical symbols are by them selves they
  are called elements
• But when chemical symbols combine, they are
  called......

Chemical Formulas
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Chemical Formulas

• Chemical formulas represent different compounds
  (chemical substances)
• If chemical symbols are the letters of
  chemistry, then chemical formulas make up the
  words
• Examples in a jif

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Chemical Formulas

• H2O Fe2Cl HI CH4
• C6H12O6 CaCO3 SF6

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Chemical Formulas

• Subscripts tell us how many atoms of the
  respective element that are present in that
  chemical substance
• H2O The 2 tells us that there are 2 atoms of
  Hydrogen for every 1 atom of Oxygen present in
  water.
• If there is no subscript present, then it means
  that there is only one atom present in that
  substance

Methane Methane has four Hydrogens around one
central Carbon CH4
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Criss Cross Method of Formula Writing
Fe3 O2- ? Fe2O3
Fe
O
3
-2
Fe2O3
Criss-Cross will make ya JUMP JUMP!
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Criss Cross Method of Formula Writing
Na1 Br-1 ? NaBr
Na
Br
1
-1
Na Br
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1 - 2 Not Balanced
Na 1
O -2
Na 1
Na 1
O -2
1 x (-2) -2
2 x (1) 2
2 (- 2) 0 Balanced Na2O
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3 -2 Not Balanced
O -2
Al 3
Al 3
O -2
Al 3
O -2
O -2
3 x (-2) -6
2 x (3) 6
6 (- 6) 0 Balanced Al2O3
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4) Types of Compounds

• b) Tertiary form from polyatomic ions which
  consists of a group of atoms covalently bonded
  with a single charge that bond ionically with
  other ions.
• Ex.
• ammonium sulfate ,

NH41
SO4-2
(NH4)2SO4
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Criss Cross Method of Formula Writing with
Polyatomic Ions
NH41 O-2 ? (NH4)2O
NH4
O
1
-2
(NH4)2O
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5) Polyvalent Metals

• Some metals including, but not limited to the
  transition metals do not follow the octet rule
  and may form more than 1 kind of cation. These
  ions are named with roman numerals to
  distinguish between them.
• Ex) Fe2 iron (II) read iron two
• Fe3 iron (III) read iron three
• FeCl2
• FeCl3
• Copper (I) sulfate
• Copper (II) phosphate

iron (II) chloride
iron (III) chloride
Cu2SO4
Cu3(PO4)2
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Naming Ionic Compounds

• Binary Compounds

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Rules for Naming Ionic Compounds

• For the Cation
• Borrow the name of the element
• Ex. K is the Potassium Ion
• Ex. Zn2 is the Zinc Ion
• If an ion has more than one oxidation state
• Cu1 is copper one ion
• Cu2 is copper two ion

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Rules for naming the anion

• Anion- the negatively charged atom
• Use the name of the element followed by the
  suffix -ide
• Cl- is the Chloride ion
• O-2 is the Oxide ion
• P-3 is the Phosphide ion

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Naming Ionic Compounds

• When naming ionic binary compounds
• Name the cations element name followed by the
  anions name
• NaCl is Sodium Chloride
• K2O is Potassium Oxide
• CuCl2 is Copper (II) Chloride
• Mg3N2 is Magnesium Nitride
• Al2S3 is Aluminum Sulfide

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Naming Ionic Compounds with Polyatomics

• Name the Cation
• Name the Polyatomic ion
• Ex. Mg3(PO4)2
• Magnesium Phosphate

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Name this compound
X

• FeO
• If thats correct, name this
• Fe2O3
• How can we distinguish between these compounds?
• What is the charge on the oxygen in each
  compound? Then what is the charge on the iron in
  each compound?
• Fix the name of the first compound

Iron (II) oxide
Iron oxide
Fe2 O-2
Iron (III) oxide
Fe3 O-2
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Bonding Objectives
Chem 5.0 Bonding, Formulas and Naming - OBJECTIVES










Describe Ionic Bonding Theory.
Describe Covalent Bonding Theory.
Write formulas and names for ionic compounds
including binary, tertiary and polyvalent.
Write formulas and names for molecules
(covalent compounds.)
Write formulas and names for hydrates.
Write formulas and names for binary and
tertiary acids.
Write Lewis-Dot structures for ionic compounds.
Write structural formulas for covalent
compounds.
Describe electronegativity and how it affects
bond type ionic, polar covalent and
nonpolar covalent.
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6) Lewis Dot Diagrams for elements
Element of val. Electrons Dot Diagram
Li Li?
N
Be
F
Ne
Au
1
5
2
7
8
2
Note Only show s and p orbitals in dot diagram.
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• Electron Dot Diagram for Atoms and Ions

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7) Lewis-dot diagram for sodium chloride
Na -
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Lewis-dot diagram for NaCl
Ionic Bond Formed
Na
Na
Na
-
Na -
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Bonding Objectives
Chem 5.0 Bonding, Formulas and Naming - OBJECTIVES










Describe Ionic Bonding Theory.
Describe Covalent Bonding Theory.
Write formulas and names for ionic compounds
including binary, tertiary and polyvalent.
Write formulas and names for molecules
(covalent compounds.)
Write formulas and names for hydrates.
Write formulas and names for binary and
tertiary acids.
Write Lewis-Dot structures for ionic compounds.
Write structural formulas for covalent
compounds.
Describe electronegativity and how it affects
bond type ionic, polar covalent and
nonpolar covalent.
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B. Covalent Bonding

• 1) Covalent Bonds are formed by sharing pairs of
  
• electrons between 2 atoms.
• 2) Usually formed between two nonmetals with a
  low electronegativity difference.
• 3) Molecules
• a) a group of atoms held together by covalent
• bonds
• b) molecular substance contains molecules

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4) Naming

• uses prefixes 1 mono- 4 tetra- 7 hepta-
  10 deca-
• 2 di- 5 penta- 8 octa-
• 3 tri- 6 hexa- 9 nona-
• b) end in ide
• c) More electronegative element is written last
• d) Only use a prefix on the first element if it
  is more than one.
• e) Always use a prefix for the second element.
• Ex) water H2O dihydrogen monoxide
• smog NO2 nitrogen dioxide

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SF6 (Sulfur Hexafluoride)

• Cool little video

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5) Types of formulas for covalent bonding

• a) Molecular Formula shows how many atoms make
  up a compound.
• ex. CH4 H2O
• b) Structural Formula shows how the atoms are
  bonded to each other.
• ex.

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• 1. Uses 2 dots to show an unshared pair of
• electrons.
• 2. Uses dashes to represent covalent bonds (a
• shared pair of electrons) in a structural
  formula.
• 3. The octet rule should be satisfied for each
  element in the compound.
• c) Empirical Formula is the lowest whole number
  ratio of all the elements in the compound.
• Ex) C6H6 CH
• C6H12O6 CH2O

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6) Multiple Bonds can be used to satisfy
the octet rule

• Single Bonds Share 1 pair of electrons.
• Ex) methane or phosphorous trichloride

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• Double Bonds Share 2 pairs of electrons.
• Ex) formaldehyde

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• Triple Bonds Share 3 pairs of electrons
  (strongest bond).
• Ex) ethyne

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Bonding Objectives
Chem 5.0 Bonding, Formulas and Naming - OBJECTIVES










Describe Ionic Bonding Theory.
Describe Covalent Bonding Theory.
Write formulas and names for ionic compounds
including binary, tertiary and polyvalent.
Write formulas and names for molecules
(covalent compounds.)
Write formulas and names for hydrates.
Write formulas and names for binary and
tertiary acids.
Write Lewis-Dot structures for ionic compounds.
Write structural formulas for covalent
compounds.
Describe electronegativity and how it affects
bond type ionic, polar covalent and
nonpolar covalent.
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8) Properties of Covalent Bonds

• a) Low melting points, brittle, strong odor, poor
  conductors of electricity.
• b) Polar Bonds form between elements with large
  differences in electronegativity. These have an
  uneven sharing of electrons.
• Ex) water

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Ionic or Covalent?

• Polar-covalent bonding- a covalent bond in which
  the bonded atoms have an unequal attraction for
  the shared electrons

In the fight for electrons, Igor wins (most of
the time)
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• c) Nonpolar bonds exert equal pull on the
  electrons.
• Ex) O2

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Ionic or Covalent?

• Nonpolar covalent bonding- A covalent bond in
  which the bonding electrons are shared equally by
  the bonded atoms, resulting in a balanced
  distribution of electrical charge

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• 9) Electronegativity Chart is used to determine
  bond type
• non polar covalent polar covalent
  ionic bonds

0
1.9
0.4
4.0
even sharing
electrons transferred
uneven sharing
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C. Ionic Covalent Bonds Summary
Ionic Bonding Covalent Bonding









metal-nonmetal
nonmetal-nonmetal
e- transferred
e- shared
large electronegativity difference (gt1.9)
electronegativity difference (0 ?1.9)
ions formed
no ions
written cation () anion (-)
more electronegative element written last
name cation - name anion
use prefixes/ends in ide
forms ionic compound (formula unit) in a crystal
lattice
forms molecules
Written with a chemical or empirical formula
Written with a molecular or structural formula
NaCl sodium chloride
CCl4 carbon tetrachloride
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carbon tetrachloride
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Bonding Objectives
Chem 5.0 Bonding, Formulas and Naming - OBJECTIVES










Describe Ionic Bonding Theory.
Describe Covalent Bonding Theory.
Write formulas and names for ionic compounds
including binary, tertiary and polyvalent.
Write formulas and names for molecules
(covalent compounds.)
Write formulas and names for hydrates.
Write formulas and names for binary and
tertiary acids.
Write Lewis-Dot structures for ionic compounds.
Write structural formulas for covalent
compounds.
Describe electronegativity and how it affects
bond type ionic, polar covalent and
nonpolar covalent.
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D. Acids

• 1) A molecular compound that dissolves in water
  to produce H and a characteristic anion.
• 2) In water, acids behave like ionic compounds.
• 3) Most acid formulas begin with H. (Except
  organic acids) COOH
• 4) The number of hydrogens in the formula depends
  upon the charge of the anion.

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5)Types of Acids

• a.) Organic Acids contain the carboxylic group,
• -COOH or
• Ex) CH3COOH acetic acid (vinegar)

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b.) Binary Acids contain hydrogen and 1 type of
anion.

• A two-word name is used for binary acids.
• 1st word prefix is hydro
• root is formed from the anion
• anion suffix ide is changed to ic
• 2nd word is acid
• Ex) HCl anion is chloride
  hydrochloric acid
• Prefix root suffix
• HBr anion is bromide hydrobromic acid

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c.) Oxo (Tertiary) Acids contain oxygen within a

polyatomic ion.

• A two-word name is used for oxo acids.
• H2SO4
• H2SO3
• sulfur or phosphor (to sound better)
• 2nd word is acid
• If you ate something you dont like,
• you say ic

sulfate
sulfuric acid
sulfite
sulfurous acid
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• HNO3 anion is nitrate nitric
  acid
• root suffix
• H3PO3 anion is phosphite
• Nitrous acid, anion is formula is
• Phosphoric acid, anion is
• formula is

phosphorous acid
nitrite
HNO2
phosphate
H3PO4
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E. Hydrates

• 1.) Ionic compounds that absorb H2O into their
  solid structures.
• Ex) magnesium sulfate heptahydrate (epsom salt)
  
• Formula MgSO4 ? 7H2O
• 2.) Anhydrous substance substance without water
  MgSO4
• Ex) CuSO4 5H2O
• CuSO4 anhydrate (light blue/white)

copper (II) sulfate pentahydrate (bright blue)