Transcript NAMING AND WRITING CHEMICAL COMPOUNDS

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IUPAC
BOHR DIAGRAMS FOR ATOMS
TYPES OF CHEMICAL BONDS
MOLECULAR COMPOUNDS
◦ TYPES
 SIMPLE COVALENT
 COMMON NAME
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IONIC COMPOUNDS
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SIMPLE IONIC
MULTIVALENT
POLYATOMIC/COMPLEX
HYDRATED IONIC
ACIDS
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International Union of Pure and Applied
Chemists
This is a global organization that sets the
standards in chemistry.
One job of the IUPAC is to give compounds
SYSTEMIC NAMES.
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Bohr diagrams, also called
ENERGY LEVEL DIAGRAMS,
are a means of drawing
atoms in a 2-D manner.
Keep in mind that atoms are
actually 3-D, and there are
more complex
representations of atoms.
Bohr models always include
the NUCLEUS and the
ELECTRON ENERGY LEVELS of
an atom.
LINK
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There are 3 types of
SUBATOMIC PARTICLES
found in the atom:
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PROTONS (p+)
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ELECTRONS (e-)
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NEUTRONS (no)
◦ Positively charged particles with a significant mass
◦ Atomic Number = Number of Protons
◦ Negatively charged particles with an insignificant mass
◦ Number of Electrons = Number of Protons
◦ Neutral particles with a significant mass
◦ Number of neutrons = Atomic Mass – Atomic Number
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NUCLEUS
◦ Center of the atom, contains protons and neutrons
◦ The atomic mass is concentrated here
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ELECTRON ENERGY LEVELS
◦ Particular areas around the nucleus where electrons
are likely to be found
◦ Electrons DO NOT exist BETWEEN energy levels
◦ 3 LEVELS:
 FIRST LEVEL (Closest to Nucleus)
 SECOND LEVEL
 THIRD LEVEL (Outermost)
2 e8 e8 e-
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VALENCE LEVEL
◦ DEFINITION: Outermost energy level of an atom
◦ Electrons in this level are called VALENCE ELECTRONS
◦ Atoms with FULL valence shells are STABLE, meaning
they will not bond with other atoms in normal
conditions.
◦ The atoms of Group 18, the Noble Gases, have full
valence levels.
◦ Atoms that do not have full electron energy levels are
unstable and must GAIN, LOSE, or SHARE electrons to
become stable.
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ATOMIC NUMBER
◦ Located in the top of each element box
on the periodic table.
◦ ATOMIC NUMBER = # OF PROTONS
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ATOMIC MASS (MOLAR MASS)
◦ Located in the bottom of each element box on the
periodic table.
◦ Round it off for calculations.
◦ ATOMIC MASS = # OF PROTONS + # OF NEUTRONS
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EXAMPLE:
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Li – lithium atom
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DRAW BOHR DIAGRAMS FOR:
ATOMIC # =
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ATOMIC MASS = _____________
# p+ = ________________________
# e- = ________________________
# no = ________________________
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EXAMPLE:
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Ne – neon atom
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DRAW BOHR DIAGRAMS FOR:
ATOMIC # =
_____________
ATOMIC MASS = _____________
# p+ = ________________________
# e- = ________________________
# no = ________________________
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EXAMPLE:
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S – sulfur atom
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DRAW BOHR DIAGRAMS FOR:
ATOMIC # =
_____________
ATOMIC MASS = _____________
# p+ = ________________________
# e- = ________________________
# no = ________________________
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Do worksheet in booklet on
following page!!!
For complete answers be
sure to do the following:
◦ Write in the atomic number
and mass number.
◦ Write the name of the atom in
the bottom of the square.
◦ Include protons and neutrons
in the nucleus of the atom.
◦ Write electrons in the energy
levels outside the nucleus.
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CHEMICAL BONDS
◦ DEFINITION:
 A force of attraction between atoms.
◦ There are 2 TYPES of Chemical bonds
 Covalent
 Ionic
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COVALENT BONDS
◦ AKA: molecular bonds
◦ “co” – together/sharing , “valent” – outer shell
◦ DEFINITION:
 A SHARING of ELECTRONS between 2 atoms
 BETWEEN a two or more NONMETALS
◦ Solutions of covalently bonded substances are
NON-ELECTROLYTIC.
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IONIC BOND
◦ DEFINITION:
 A TRANSFER of ELECTRONS between two atoms
 BETWEEN a METAL and a NONMETAL
◦ Solutions of ionic bonded substances are
ELECTROLYTIC.
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COMPOUNDS consist of atoms or ions of
two or more elements bonded together.
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Forms when 2 or more NONMETALS share
electrons in COVALENT BONDS.
2 TYPES:
◦ BINARY Molecular Compounds
◦ TRIVIAL NAME Molecular Compounds
Also called SIMPLE molecular compounds.
 Binary Molecular Compounds use IUPAC
prefixes:
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◦ We will write these prefixes in the following
Number
Prefix
table.
1
mono
2
di
3
tri
4
tetra
5
penta
6
hexa
7
hepta
8
octa
9
nona
10
deca
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RULES:
1. Write NAMES of elements, with the 2nd
element ending in “-ide”.
2. Add PREFIXES to indicate HOW MANY ATOMS
of each element.
3. Do NOT use the prefix “mono” for the 1 st
element, only with the 2nd element.
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N2O4
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P2O5
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CCl4
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RULES:
1. Write ELEMENT SYMBOLS for each element in
the compound.
2. Use the PREFIX in the name to determine
NUMBER OF ATOMS, and write that number
as a SUBSCRIPT next to the symbol (no
subscript for 1 atom).
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carbon monoxide
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triphosphorus pentabromide ____________
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sulfur hexafluoride
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Also called COMMON NAME molecular
compounds.
There are SOME molecular compounds that go by their COMMON
NAMES, and we must memorize these names.
FORMULA
TRIVIAL/COMMON NAME
O3
ozone
H2O
water
H2O 2
hydrogen peroxide
NH3
ammonia
CH4
methane
CH3OH
methanol
C2H5OH
ethanol
C6H12O6
glucose
C12H22O11
sucrose
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Complete the NEXT THREE SHEETS in your
handout for HOMEWORK.
Refer to the following notes for help:
◦ FIRST SHEET
 Given Name, Write Formula Notes
◦ SECOND SHEET
 Given Formula, Write Name Notes
◦ THIRD SHEET
 Everything!
 Watch out for those common name molecular
compounds!!!
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IONS
◦ RECALL:
 AS mentioned earlier, atoms other than the
NOBLE GASES are unstable, and need to GAIN,
LOSE, or SHARE ELECTRONS to become more
stable.
 If they SHARE electrons, this forms a COVALENT
BOND to another atom.
 If they LOSE or GAIN electrons, atoms become
IONS and form IONIC BONDS with other atoms.
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OCTET RULE
◦ Atoms that have an octet of valence electrons
are STABLE and UNREACTIVE.
Ions are charged atoms that have lost or
gained electrons to achieve the valence
configurations of a noble gas.
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◦ CATIONS:
 POSITIVE ions that are formed from a LOSS of
electrons.
 It has more PROTONS than ELECTRONS and
therefore has a net POSITIVE charge.
 METALS form cations.
 MEMORY TOOL: t in “cation” resembles a “+” sign
 EXAMPLE: lithium ion
Li+
1+ charge
◦ ANIONS:
 NEGATIVE ions that are formed from a GAIN of
electrons.
 It has more ELECTRONS than PROTONS and
therefore has a net NEGATIVE charge.
 change the ending of the name of anions to -ide
 NONMETALS form anions.
 MEMORY TOOL: A Negative ION
 EXAMPLE: fluoride ion
F1- charge
 LINK
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METALS
◦ ATOMS of METALS will LOSE electrons to become CATIONS.
◦ ATOMS with 1, 2, or 3 VALENCE electrons will LOSE these
electrons to form 1+, 2+, or 3+ ions respectively.
◦ GROUP 1 ATOMS – ALKALI
 1 valence electrons(s) (will lose 1 to become stable)
 1 + ion
◦ GROUP 2 ATOMS – ALKALINE EARTH
 2 valence electrons(s) (will lose 2 to become stable)
 2 + ion
◦ GROUP 13 ATOMS
 3 valence electrons(s) (will lose 3 to become stable)
 3 + ion
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NONMETALS
◦ ATOMS of NONMETALS will GAIN electrons to become ANIONS.
◦ ATOMS with 5,6, or 7 VALENCE electrons will GAIN these electrons to form 3-,
2-, or 1- ions respectively.
◦ GROUP 15 ATOMS
 5 valence electrons(s) (will gain 3 to become stable)
 3 - ion
◦ GROUP 16 ATOMS
 6 valence electrons(s) (will gain 2 to become stable)
 2 - ion
◦ GROUP 17 ATOMS - HALOGENS
 7 valence electrons(s) (will gain 1 to become stable)
 1 - ion
◦ GROUP 18 ATOMS - NOBLE GASES
 FULL outer valence levels
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Note that in BOHR DIAGRAMS for IONS,
electron numbers have changed.
Here is a quick equation for calculating the
number of electrons:
#
e
=
+
#p
- charge
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A sodium ATOM and a sodium ION
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A chlorine ATOM and a chloride ION
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Complete the next two worksheets in your
booklet for homework!
Do a few examples of each page in class so
that when you go home, you know what you
are doing!!!
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Form when at least 1 METAL AND 1
NONMETAL transfer electrons in an IONIC
BOND.
Metals will become CATIONS and LOSE
electrons and nonmetals will become
ANIONS and GAIN electrons.
These ions, with opposite charges, attract
and form IONIC BONDS.
Unlike covalent bonds, these bonds are not
“ACTUAL BONDS,” but forces of attraction
between oppositely charged ions.
They stay together in a CRYSTAL LATTICE.
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Example: NaCl (Draw on your sheet)
Cl-
Na+
Cl-
Na+
Cl-
Na+
Na+
Cl-
Na+
Cl-
Na+
Cl-
Cl-
Na+
Cations are surrounded by anions and vice versa
Also refer to Figure 4, p. 189
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Example: NaCl
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3 TYPES:
◦ Binary Ionic Compounds
 SIMPLE
 MULTIVALENT
◦ Polyatomic Ionic Compounds
◦ Hydrated Ionic Compounds
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“Binary”
 Only 2 types of ions involved.
SIMPLE IONIC COMPOUNDS
◦ Simple ionic compounds are composed of a metal ion
(+) and a nonmetal ion(-).
GIVEN FORMULA, WRITE NAME
◦ RULES:
1. Write the name of the CATION before the ANION
(Be positive before being negative  )
2. Change the ending of the ANION name to “-ide”
3. Do not use CAPITALS, Do not use PREFIXES!
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EXAMPLE:
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MgBr2
KCl
Na2S
Mg3P2
Ba3N2
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WHAT’S WRONG WITH THE FOLLOWING
NAMES FOR BaS?
◦ barium sulfur
◦ Barium Sulfide
◦ barium sulfuride
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Do the following sheet in the booklet for
homework:
Follow rules for:
◦ “GIVEN FORMULA, WRITE NAME” for Ionic
Compounds.
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GIVEN NAME, WRITE FORMULA
◦ RULES:
1. Write element symbols.
2. Look up the ION CHARGE on the periodic
table.
3. Use the “crossover” method to determine
the numbers of each ion in the compound.
4. Ion ratios are always in the lowest
common multiple.
5. Ion charges must add up to “zero” overall.
EXAMPLE:
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sodium bromide
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barium iodide
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EXAMPLE:
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magnesium oxide _____________________
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aluminum oxide ___________________
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Do the next two sheets
for homework!
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FIRST PAGE:
◦ Given NAME, Write
FORMULA
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SECOND PAGE:
◦ TOP HALF – Molecular
Compound Naming
◦ BOTTOM HALF – Ionic
Compound Naming