Transcript Notes: Naming and Writing Ionic Compounds

Types of Bonding
There are two types of
bonds:
• Ionic bonds
• Covalent bonds
IONIC
BONDING
Ionic Bonding
• Occurs between a metal and a
nonmetal
• Ionic Bond - Electrons are
transferred from one atom
to the other
Properties
• Ionic compounds have high melting
points (meaning they are very strong)
• Ionic compounds are also very brittle
• Ionic compounds usually dissolve in
water (these solutions are good
conductors of electricity)
The Octet Rule
• Octet Rule – atoms tend to gain, lose,
or share electrons in order to acquire a
full set (8) valence electrons
• Remember that is the goal of atoms to
have the electron configuration of
noble gases
Lewis Dot Diagrams
• The valence electrons are the only
ones that will participate in bonding so
we will concentrate on those.
• In Lewis Dot Diagrams we use dots to
represent electrons around the symbol
of an element to allow people to see
how many valence electrons they have
An Example:
Carbon has 4 valence electrons:
C
We use the dots to represent the
valence electrons!
• Draw the Lewis dot structures for Li + O
Li O Li
• What is the formula?
Li2O
Writing Ionic
Bonds
Recap
• Ionic bond forms between–metal and a non-metal
• Electrons are–transferred from the metal to the
non-metal
Rules for writing the formula
1. Write the symbol and the oxidation
number (common ion), putting the
positive charge first.
2. Switch the oxidation numbers, re-write
them as subscripts without their charges.
3. Reduce the subscripts if you can.
EX
1.
2.
3.
Magnesium and Oxygen
Transition Metals
• What is their common ion??
– It will change depending on the element that
they are bonding with.
• Roman numerals will tell you the oxidation
number. It’s always given to you.
EX
1.
2.
3.
Nickel (IV) and Sulfur
Your turn
Write the chemical formula for the following
ionic compounds
• Sodium and iodine
• Barium and oxygen
• Potassium and sulfur
• Magnesium and phosphorous
Polyatomic Ions
We have dealt with ions like Na+ or Cl…those are monatomic ions (ions
consisting of only one atom).
Another important group
exists…polyatomic ions. They
consist of more than one atom and still
have either a positive or negative
charge.
Polyatomic ion• Names sometimes end in –ate or –ite
**Rules stay the same for bonding but
also…
–Treat the ion like a single atom
–Always use ( )
EX
Calcium Perbromate
1.
2.
3. Never Change what is inside
the ( )-Cannot be reduced because the 4 is
inside the ( )
Your turn
Write the formula for the following compounds:
– Sodium and chlorate
– Barium and nitrate
– Ammonium and selenium
– Ammonium and phosphate
Two Types of Ionic Compounds
• Binary- consists of only 2 types of
elements (ex: HBr)
• Ternary- consists of more than 2 types of
elements (ex: NaNO3)
– These will have polyatomic ions
How to Name- binary
1. Write the name of the first element from
the periodic table
2. Write the name of the second element
drop the ending and add –ide
Some examples:
a) NaCl is sodium chloride
b) BaF2 is barium fluoride
Now you try:
c) Al2S3 and d) CaO
How to Name- ternary
1. Write the name of the first element from
the periodic table
2. Write the name of the second group just
like it is on the list
Some examples:
a) KNO3 is potassium nitrate
b) MgSO3 is magnesium sulfite
Now you try:
c) CaCO3 and d) NaOH
Exception
• Ammonium, NH4
+1
• Examples:
NH4Cl
ammonium chloride
and
NH4NO3
ammonium nitrate
Practice Naming Compounds
Determine if the compound is binary or
ternary, then name it:
1. Li3P
Binary, lithium phosphide
2. Ca3N2
Binary, calcium nitride
3. KCl
Binary, potassium chloride
4. NaClO3
Ternary, sodium chlorate
5. (NH4)2Se
Ternary, ammonium selenide