Chapter 7
Nomenclature
writing chemical formulas
naming chemical compounds
potassium chromate
potassium dichromate
1
Sodium and Chlorine
Na Cl
+
Na
Cl
NaCl
1A 2A
1+
8A
3A 4A 5A 6A 7A
1B 2B 3B 4B 5B 6B 7B 8B 9B 10B
1-
Sodium Chloride
•
Cation 1st: name of element
•
Anion 2nd: root and add -ide
•
When combined together
✓ Metals lose e- (+ ion = cation)
✓ Nonmetals gain e- (- ion = anion)
✓ Ionic Compounds (Type I Binary Ionic)
2
Magnesium and Fluorine
Mg
F
1A 2A
8A
3A 4A 5A 6A 7A
12+ 1B 2B 3B 4B 5B 6B 7B 8B 9B 10B
2+
Mg
F
MgF2
•
•
The number of electrons lost must equal the
number of electrons gained
The total + and - charge must add to 0
Magnesium Fluoride
3
Aluminum and Oxygen
Al
O
1A 2A
8A
3A 4A 5A 6A 7A
3+
Al
2O
2-
+ 1B 2B 3B 4B 5B 6B 7B 8B 9B 10B 3+
Al2O3
Aluminum Oxide
•
•
The number of electrons lost must equal the
number of electrons gained
Overall charge = 0
4
Write the chemical formula for
strontium sulfide
SrS
•
You might have criss-crossed to Sr2S2
but then you must reduce it to the
lowest whole number ratio.
• remember always write ionic formula in
lowest whole number ratio
5
Write the chemical formula for
potassium nitride
K3N
•
+1
-3
K N
6
The Periodic Table
1A
2A
8A
3A
Na Mg
K
1B
2B
3B
4B
5B
6B
7B
8B
9B
10B
Al
4A
5A
6A
7A
N
O
F
P
S
Cl
Ca
7
Write the chemical formula for
gallium oxide
•
+3
-2
Ga O
Ga2O3
8
Write the chemical formula for
potassium sulfide
•
+1
-2
K S
K2 S
9
Write the chemical name for
CaBr2
Remember:
• the metal (cation is 1st)
• the nonmetal (anion is 2nd : root and -ide)
Calcium Bromide
10
Chemical formula for copper
fluoride
1A 2A
Oxidation states for
Copper:
1+: Cu(I)
2+: Cu(II)
8A
3A 4A 5A 6A 7A
1B 2B 3B 4B 5B 6B 7B 8B 9B 10B
2+
1+ 2+
Know F• The number of electrons lost =
the number of electrons gained
• Overall charge = 0
• so use Cu+ or Cu(I)
• CuF
Roman Numerals refresh
1: I
2: II
3: III
4: IV
5: V
6: VI
7: VII
11
Chemical formula for copper(II)
fluoride
1A 2A
8A
3A 4A 5A 6A 7A
Copper:
1+: Cu(I)
2+: Cu(II)
F
1B 2B 3B 4B 5B 6B 7B 8B 9B 10B
2+
1+ 2+
CuF2
Roman numeral tells you the
charge on copper
Cu(II) = Cu2+
12
Write the chemical formula for zinc
chloride
1A 2A
8A
3A 4A 5A 6A 7A
1B 2B 3B 4B 5B 6B 7B 8B 9B 10B
2+
1+ 2+
ZnCl2
•
Remember that zinc is one of the
transition metals that does not require a
Roman #, since it’s oxidation state is
always +2.
13
Write the chemical formula for
chromium (VI) sulfide
•
•
•
•
The Roman # tells you the +6 charge on
the chromium metal
+6
-2
Cr S
You might have criss-crossed to Cr2S6
but then you must reduce it to the
lowest whole number ratio.
CrS3
14
Write the name for Fe2O3
•
you can un-criss-cross
• or you can determine the charge on iron
by working from the charge on the anion
• iron(III) oxide
15
Write the name for Ag2S
1A 2A
8A
3A 4A 5A 6A 7A
•
No need for a
Roman # since
silver is always
+1
1B 2B 3B 4B 5B 6B 7B 8B 9B 10B
2+
1+ 2+
(memorize along
with Zn and Cd)
Silver sulfide
16
Write the name for Cu2O
You can “un-criss-cross”
• or you can work into the cation by
knowing that the anion is -2
•
✓
✓
✓
•
The total + and - charge must add to 0
this means that electrons lost = electrons gained
the Roman # = the individual oxidation state of one of
the metal ions (not the total metal charge)
Copper (I) oxide
17
Write the name for CrP2
•
you can’t just un-criss-cross because
this is a formula which has been
reduced.
work off the non-metal’s charge
✓ remember the total + must equal - that
means the e- lost = e- gained
✓
chromium (VI) phosphide
18
Roadmap for Naming Binary Compounds
19