Transcript OGT Science Bootcamp

Binomial Nomenclature
1
2 types of chemical compounds that we will
name:
•Binary ionic - metal ion – nonmetal ion
•Binary molecular - two nonmetals
2
Tips to keep in mind when naming and writing
formulas:
•Always keep your Periodic Table handy!
•Metals (except Hydrogen) are found to the left of
the stairstep on the Periodic Table.
•Nonmetals are found on the right side of the
Periodic Table.
•Transition Metals are found to the right of Group
2 to the stairstep (except aluminum which is a
regular metal)
3
4
Naming Binary Ionic Compounds
5
 When naming, metals always come before the non-
metal (Al and F)
•
If the first ion is a transition element other than zinc,
cadmium, or silver, you must use a Roman Numeral with
the name – we’ll discuss this later.
 Name the first element as is and follow with the
second element ending in “ide”
Examples
NaCl
Sodium
Chloride
CaO
Calcium
Oxide
Al2S3
Aluminum
Sulfide
MgI2
Magnesium
BaNa2
Name the metal
ion
Name the
nonmetal ion,
changing the
suffix to –ide.
You should recognize a problem with this one
Iodide
This is two metals – not a binary ionic compound.
The name of this is Banana (JOKE – haha)
6
What about the transition metals and using roman
numerals? How does that work? Let’s see.
FeO
Iron
II Oxide
Notice – metal and nonmetal.
Name the first ion. Since the first ion is a transition
element, you must use a Roman Numeral to represent
the charge.
How do you know the charge?
Deductive reasoning.
All compounds are neutral.
Oxygen has a -2 charge (group 16)
Isn’t this easy and
FUN!!!
Therefore ….. Iron must have a +2 charge since there
is one iron and one oxygen. Iron gets a Roman
Numeral II.
7
Cu2S
Name the first ion. Since it is a transition metal, you
must use a Roman Numeral.
Which Roman Numeral? The Roman Numeral is the
same as the charge of the ion.
How do you find the charge?
Deductive reasoning!
All compounds are neutral
Sulfur has a -2 charge (group 16)
There are two coppers.
Therefore each copper must have a +1 charge
for all ions to be neutral
Copper (I)Sulfide
8
So why must we use Roman Numerals with transition
elements?
The metals in groups 1, 2, and 3 have single, definite charges.
Group 1 metals have a +1 charge.
Group 2 metals have a +2 charge.
Group 13 metals have a +3 charge.
Transition metals may have multiple charges – usually two different
positive charges.
For example, there are two copper oxide compounds:
Cu2O and CuO
Copper (II)
(I) oxide
oxide
Copper is +2
+1
We can’t just say Copper oxide. Which one of these is
Copper oxide? We must distinguish these by using a
Roman Numeral
9
There are three transition elements which do not require a
Roman Numeral because they have single definite charges.
These are:
You
need
to
Zinc –
remember
the
charges
+2
Cadmium – Cd
for
these.
+1
Silver – Ag
Ag O
Name the first ion.
No Roman
Name the second ion changing Numerals
oxide
Silver
the suffix to –ide.
needed for
Name the first ion.
ZnCl
these.
Zn+2
2
2
Zinc
chloride
Name the second ion changing
the suffix to –ide.
10
Sometimes you will see the transition elements named
using common names. Transition metals named with
Roman Numerals involves stock names.
•The common names use the Latin derivative of the
element’s name with a suffix of either –ous or –ic.
•The –ous suffix name corresponds with the smaller
charge.
•The –ic suffix name corresponds with the larger
charge.
Cuprous = Copper (I)
Cupric = Copper (II)
Plumbous = Lead (II)
Plumbic = Lead (IV)
Ferrous = Iron (II)
Ferric = Iron (III)
There are many more – just be familiar with
these six common names.
11
In Summary
Stock name
Common Name
Copper I
Cuprous
Copper II
Cupric
Iron II
Ferrous
Iron III
Ferric
Lead (II)
Plumbous
Lead (IV)
plumbic
12
The Next Category of Compounds – Binary
Molecular
These compounds contain two elements (binary).
The term “molecular” indicates that these
elements are joined by a covalent bond.
They must therefore be nonmetals.
Bottom line – 2 elements – both nonmetals
To name and write formulas for these, you must
know some numerical prefixes.
13
Naming Covalent Bonds
14
 To name covalent compounds we use numerical
prefixes to tell the # of atoms of each element in a
molecules.
Prefix
Mono
Di
Tri
Tetra
Penta
Hexa
Hepta
Octa
Nona
Deca
Number
1
2
3
4
5
6
7
8
9
10
 Exception- Don’t use mono- before the first element
Wrong- CO- monocarbon monoxide
 Correct- CO- carbon monoixde

 Just like ionic bonds, the ending of the second
element is still changed to “ide”.
CO2
Carbon dioxide
CO
Name the first element. Since
there is only one, no prefix is
needed. The second element
always gets a prefix and a suffix
of –ide.
Carbon monoxide
N2O4
Dinitrogen tetraoxide
CCl4
Carbon tetrachloride
15
Name the first element.
Since there are two
present, the prefix “di” is
needed. The second
element always gets a
prefix and a suffix of –ide.
AlCl3
What do you think about this one???
Be careful. This is a metal and nonmetal.
Always keep your Periodic Table in front of you for
reference.
You may have been tempted to say “aluminum trichloride”.
This is INCORRECT!
This is a binary IONIC compound. No prefixes are used.
Simply aluminum chloride.
16
Silicon dioxide
SiO2
Silicon and oxygen are both
nonmetals.
The lack of a prefix on silicon means
that there is only ONE silicon.
The prefix “di” in front of oxide means
that there are TWO oxygens.
Diphosphorous pentachloride
P2Cl5
Phosphorous and chloride are both nonmetals.
The prefix “di” means that there are TWO
phosphorouses (Is that a word?)
The prefix “penta” before chlorine means that
there are five chlorines.
17
S,
O
SO2, sulfur dioxide
18
S,
F
C,Cl
N,I
SF2,sulfur difluoride
CCl4, Carbon tetrachloride
NI3,Nitrogen triiodide
You Try!
Nitrogen monoxide
NO
Nitrogen and oxygen are both
nonmetals.
The lack of a prefix on nitrogen
means only ONE nitrogen.
The prefix “mono” on oxygen
indicates ONE oxygen.
Is this not sooooooo easy!??
19
Reivew!!!
20
1. P4S5
2. N2O3
3. Na3N
4. Ni2S3
5. CuF2
6. CoS
7. CsI
8. Cl2O
Prefix
Stem or root of
nonmetal
Suffix
Hydro- < NM > -ic
Acid
HCl is a binary acid – hydrogen - nonmetal
HCl
Hydrochloric Acid
HI
Hydroiodic Acid
H2S
Hydrosulfuric Acid
21
Writing Formulas for Ionic Compounds
22
List the symbol for each ion and its charge
1.

Ie. Al3+F-
2. Find the least common multiple of the ion’s
charges to make the compound neutral


The least common multiple of 3 and 1 is 3
You only need 1 Al but 3 F
3. Write out the formula with subscripts

AlF3
23
Ionic Formulas- Criss-Cross Method
 Cross down the charge numbers and write the
correct formulas for the following cations and
anions.

Let’s try it with Mg and Br
You Try! Write out the formula and its name!
24
 Li, O
 K, Cl
 Br, Ba
Li2O, Lithium Oxide
KCl, Potassium Chloride
BaBr2, Barium Bromide
More examples: Iron (III) bromide
Fe+3
-1
Br
Br -1
Br -1
FeBr3
Write the symbol and charge of each ion.
The charge of the iron is provided by the
Roman Numeral.
Balance the charges by supplying
subscripts. The subscripts tell how many
of each ion is needed to balance the
compound.
You’ll need three bromine ions to balance
the one iron.
25
Aluminum
Sulfide
Al+3
S-2
-2
+3
S
Al
S-2
Al2S3
Write the symbol and charge of each ion.
Balance the charges by supplying subscripts.
In this case the charges do not evenly divide into each
other. You must find the least common multiple. SIX
How many aluminums are needed to arrive at a +6
charge?
2
How many sulfurs are needed to arrive at a -6 charge?
3
26
Formulas for Molecular Compounds
27
 Write the symbols for the first and second element
 Translate the prefixes into subscripts.
 Ie.
 Xenon Hexafluoride
 XF6
 You aren't balancing charges of covalent compounds!
You Try! Write out the formula for each
compound!
28
 Diarsenic pentoxide
As2O5
 Tetraphosphorus trisulfide
P4S3
 Tetraphosphorus decoxide
P4O10
 Phosphorus trichloride
PCI3