Unit Five
Nomenclature
Nomenclature Introduction
 Ionic bonds are formed when electrons are transferred
between one metal and one non-metal element.
Covalent bonds are formed when electrons are shared
between two non-metal elements. Because each bond
is different, scientists must have a specific way to name
ionic compounds, and a different way to name covalent
or metallic compounds. Today we will go through some
examples of how we name ionic and covalent
compounds and practice what we learn from the
sample problems.
Review
 1.) Ions that have a positive charge are called
 2.) Ions that have a negative charge are called
 3.) Metals tend to
 4.) Non-metals tend to
become
electrons to become
electrons to
Determine which naming system to
use FIRST
 A. Stock System (Ionic Bonds)
 Molecules involved are metals and non metals.
 B. Molecular System (Covalent Bonds)
 Molecules involved are only nonmetals.
A. Stock System (Ionic Bonds)
If the compound is Binary – contains
only 2 types of atoms.
 Ionic Compounds
 Write the full name of the 1st element.
 Write the name of the 2nd element, but change the ending
to “ide”
 Put the two together and you have the correct name for the
compound.
Example: NaFSodium Fluoride
Example One
Write the proper name for NaCl.
 Step 1: Determine the charge of the cation and anion in the
compound.
 Which element has a positive charge and is a cation?
 Which element has a negative charge and is a anion?
 Step 2: Write the name of the element that is the cation first:
 Step 3: Write the name of the element that is the anion second
but change the ending to “ide”
 Step 4: Put step 2 and step 3 together and you have the correct
name for the compound.
Example Two
Write the proper name for CaS.
 Step 1: Determine the charge of the cation and anion in the
compound.
 Which element has a positive charge and is a cation?
 Which element has a negative charge and is a anion?
 Step 2: Write the name of the element that is the cation first:
 Step 3: Write the name of the element that is the anion second
but change the ending to “ide”
 Step 4: Put step 2 and step 3 together and you have the correct
name for the compound.
Example Three
Write the proper name for LiF.
 Step 1: Determine the charge of the cation and anion in the
compound.
 Which element has a positive charge and is a cation?
 Which element has a negative charge and is a anion?
 Step 2: Write the name of the element that is the cation first:
 Step 3: Write the name of the element that is the anion second
but change the ending to “ide”
 Step 4: Put step 2 and step 3 together and you have the correct
name for the compound.
Example Four
Write the proper name for BeO.
 Step 1: Determine the charge of the cation and anion in the
compound.
 Which element has a positive charge and is a cation?
 Which element has a negative charge and is a anion?
 Step 2: Write the name of the element that is the cation first:
 Step 3: Write the name of the element that is the anion second
but change the ending to “ide”
 Step 4: Put step 2 and step 3 together and you have the correct
name for the compound.
Review Stock System (Ionic Bonds)
 Look over the flowchart to review the steps of
forming an ionic bond. Use the notes and the
flowchart to name the following ionic compounds.
1.
AgCl
6. Cr2O3
2.
NaO
7. CuO
3.
PbO
8. K3N
4.
CoCl2
9. NiS
5.
SnF2
10. SrBr2
Review Stock System (Ionic Bonds)
 Look over the flowchart to review the steps of
forming an ionic bond. Use the notes and the
flowchart to name the following ionic compounds.
11. MgI2
16. NaI
12. BaCl2
17. CrF
13. BaS
18. BaO
14. VP
19. CaF2
15. HgS
20. NaCl
21. Ag2S
A. Stock System
If the compound contains a
polyatomic ion.
Steps for naming compounds with
a polyatomic ion.
 1.) Find the polyatomic ion on
your list. Remember that most
polyatomic ions are (-) so
chances are it’s the second
thing written.
 2.) Name the first element or
polyatomic ion, and then name
the second element or
polyatomic ion.
 3.) If the second ion is not the
polyatomic atom then be sure
to add –ide.
 Examples:
Na3PO4 – Sodium Phosphate
NH4Cl- Ammonium Chloride
Example One
Write the proper name for Be(OH)2
 1.) Find the polyatomic ion on your list. Remember that most
polyatomic ions are (-) so chances are it’s the second thing
written
 2.) Name the first element or polyatomic ion, and then name
the second element or polyatomic ion. If the second ion is not
the polyatomic atom then be sure to add –ide.
Example Two
Write the proper name for Ca3(PO4)2
 1.) Find the polyatomic ion on your list. Remember that most
polyatomic ions are (-) so chances are it’s the second thing
written
 2.) Name the first element or polyatomic ion, and then name
the second element or polyatomic ion. If the second ion is not
the polyatomic atom then be sure to add –ide.
Forming Ionic Compounds
 Ionic compounds always have an
overall charge of zero
 Potassium + Oxygen=
 Criss-cross method
 Magnesium + Sulfur=
 Write the formula unit for when
magnesium and nitrogen
combine:
 Beryllium + Carbon=
 Aluminum + Phosphate=
 Potassium + Hydroxide=
A. Stock System
If the compound contains a transition
metal (D-Block)
 You must include a Roman numeral that
denotes the charge on the transition
metal.
 For instance, Fe2+ is iron (II). Fe3+ is iron
(III)
 Example:
FeBr2 Iron (II) Bromide
Example One
Write the proper name for FeO.

Step 1: Determine the charge of the cation and anion in the compound.


Which element has a positive charge and is a cation?
Which element has a negative charge and is a anion?

Step 2: Write the name of the element that is the cation first :

Step 3: Determine the charge of the cation- remember that the charges of the cation and
the anion must balance out (equal zero). Write the charge of the cation in roman numerals
in parenthesis after the cation’s symbol.

Step 4: Write the name of the element that is the anion second. If the second ion is not a
polyatomic ion then be sure to change the ending to “ide”

Step 5: Put step 3 and step 4 together and you have the correct name for the compound.
Example Two
Write the proper name for CuSO3.

Step 1: Determine the charge of the cation and anion in the compound.


Which element has a positive charge and is a cation?
Which element has a negative charge and is a anion?

Step 2: Write the name of the element that is the cation first :

Step 3: Determine the charge of the cation- remember that the charges of the cation and
the anion must balance out (equal zero). Write the charge of the cation in roman numerals
in parenthesis after the cation’s symbol.

Step 4: Write the name of the element that is the anion second. If the second ion is not a
polyatomic ion then be sure to change the ending to “ide”

Step 5: Put step 3 and step 4 together and you have the correct name for the compound.
Example Three
Write the proper name for Pb(SO3)2 .

Step 1: Determine the charge of the cation and anion in the compound.


Which element has a positive charge and is a cation?
Which element has a negative charge and is a anion?

Step 2: Write the name of the element that is the cation first :

Step 3: Determine the charge of the cation- remember that the charges of the cation and
the anion must balance out (equal zero). Write the charge of the cation in roman numerals
in parenthesis after the cation’s symbol.

Step 4: Write the name of the element that is the anion second. If the second ion is not a
polyatomic ion then be sure to change the ending to “ide”

Step 5: Put step 3 and step 4 together and you have the correct name for the compound.
B. Molecular System (Covalent Bonds)
In order to name covalent or metallic compounds, you
have to know the prefixes used to describe the
numbers scientists use in Chemistry.
1.) Use prefixes to state how many atoms are present.
 1=mono
 6= hexa
 2=di
 7=hepts
 3=tri
 8=octa
 4=tetra
 9=nona
 5=penta
 10=deca
* Mono is never used
on the first atom
written, only the
second atom.
 2.) Add the prefix to the
name of the first element
(unless there is only one
atom).
 3.) Add the prefix to the
name of the second
element. Drop the ending
of the second atom written
and add – IDE.
Example One
Write the proper name for CO2
 Step 1: Determine how many atoms are in the first element in the
compound
 Step 2: Determine what prefix this number represents
 Step 3: Add the prefix onto the front part of the elements name:
 Step 4: Determine how many atoms are in the second element in the
compound:
 Step 5: Determine what prefix this number represents:
 Step 6: Add the prefix onto the front part of the elements name and add
“ide” on to the end:
 Step 7: Add Step 3 and Step 6 together and you get:
Example Two
Write the proper name for Li2Be
 Step 1: Determine how many atoms are in the first element in the
compound
 Step 2: Determine what prefix this number represents
 Step 3: Add the prefix onto the front part of the elements name:
 Step 4: Determine how many atoms are in the second element in the
compound:
 Step 5: Determine what prefix this number represents:
 Step 6: Add the prefix onto the front part of the elements name and add
“ide” on to the end:
 Step 7: Add Step 3 and Step 6 together and you get:
Example Three
Write the proper name for P2S3
 Step 1: Determine how many atoms are in the first element in the
compound
 Step 2: Determine what prefix this number represents
 Step 3: Add the prefix onto the front part of the elements name:
NOTE: IF there is only ONE atom of the first
element- you DO NOT add the prefix mono to it. This is the ONLY exception to
the rule.
 Step 4: Determine how many atoms are in the second element in the
compound:
 Step 5: Determine what prefix this number represents:
 Step 6: Add the prefix onto the front part of the elements name and add
“ide” on to the end:
 Step 7: Add Step 3 and Step 6 together and you get:
Review Stock System (Ionic Bonds)
and Molecular System (Covalent
Bonds)
 Look over the flowchart to review the steps of forming an ionic
bond. Use the notes and the flowchart to name the following
ionic compounds.
 How do you know which naming system to use?
1. P4O10
6. SF8
2. SeCl2
7. BCl3
3. NO
8. CoCO3
4. N2O
5. NO2
9. FePO4
10.Cu2S