NAME ____________________________________ UNIT 6 (2) : REDOX NOMENCLATURE OF
INORGANIC COMPOUNDS
I-IV) Oxidation numbers through Oxidizing/Reducing Agents
V) NOMENCLATURE: (Latin: nomen = name)
CONCEPT: Nomenclature is the process of naming a compound, when given its formula
A)
Refect: We can categorize the
INORGANIC COMPOUNDS
Molecular (or Covalent)
Compounds
Ionic Compounds
They have different types of bonds & properties
so it’s reasonable that they are named differently
IUPAC strategy
Use the
Prefix system
IUPAC strategy
Use
Stock’s Nomenclature System
So when given a formula of a compound, we must know how to get to a name.....
B) Before we go any further you must understand that the “endings” of many names can help you.
 Have you noticed that many binary compounds end in –IDE? The last syllable of the
nonmetal’s element name is changed to –IDE, when a nonmetal is the more electronegative
element of the compound.
NaCl is binary inorganic with Cl as the
more electronegative element
 Have you noticed that the names of the metals never change? Given:
electronegativity values:
NaCl
0.9 vs. 3.1
The name is sodium chloride
The cation’s name is the same … the anion’s name has changed to -ide
 Have you noticed that ternary inorganics (compounds with polyatomic ions)
use the name of the polyatomic ion with no change in ending?
Given: NaNO3
The name is sodium nitrate
Notice in a ternary inorganic, there are no changes in the names
408
Structured Overview: Here is what you need to know for nomenclature strategies for inorganic compounds.
INORGANIC COMPOUNDS
Molecular (a.k.a. Covalent)
Compounds
Ionic Compounds
Use Stock’s Nomenclature system
when naming
Use the prefix system
when naming
We will name only
binary molecular
compounds using
prefixes
About endings
The more
electronegative
element’s ending
changes to -IDE
Prefixes to use are:
Mono = 1
Di
=2
Tri
=3
Tetra = 4
Pent(a) = 5
Hex(a) = 6
Hept(a) = 7
Oct(a) = 8
Non(a) = 9
Dec(a) = 10
Note that when naming binary molecular compounds,
prefixes are used rather exclusively.
But, just to confuse issues, some texts will use
prefixes also with ionic compounds. And according to
IUPAC it is acceptable to use prefixes at almost any
time. In our course, the use of prefixes will be limited
to molecules. So please highlight this. Proper
nomenclature of molecules will use prefixes. We
will work to avoid prefixes for ionic compounds.
We will name binary
ionic compounds
AND
ternary ionic compounds
with Stock’s system
When binary
When ternary
ENDINGS:
The more
electronegative
element’s ending
changes to -IDE
There are no changes in
the suffixes of any
names.
When the metal cation has more
than 1 positive oxidation state
possibility as listed on the periodic
table, include a roman numeral
that matches / identifies the value
of the oxidation state. This
enhances communication and
eliminates confusion as to the
compound’s identity.
refers to
Fe2O3 = iron(III) oxide
the +
oxidation
state
and it is different
chemically from
FeO = iron(II) oxide
409
WHEN ASKED TO NAME AN INORGANIC COMPOUND, WHEN GIVEN A FORMULA
ask if it is binary molecular then…
1) use prefixes to indicate the molar ratio of the
subscripts:
1 = mono (used generally for when the second
nonmetal, is an oxide and a halide)
2 = bi, 3 = tri, 4 = tetra, 5 = penta, 6 = hexa
7 = hepta, 8 = octa, 9 = nona, 10 = deca
2) Process: 1Name the first element using an appropriate
ask if it is binary ionic
1) Process:
ask if it is ternary ionic
1) Process:
1
Name the first species (a metal cation)
2
When the metal species is a transition metal, Pb,
Ga, In, Tl, Sn, or Bi, include the oxidation state as
a roman numeral. This applies to transition
metals
cations, & cations of the aforementioned metals.
1
Name the first species (a metal cation or polyatomic
ion such as ammonium or dimercury (I))
2
prefix to represent the subscript
I = 1, II =2, III= 3, IV = 4, V = 5, VI= 6, VII = 7
2
Name the second element, using an
appropriate prefix AND change the ending
of the second element to –IDE …& Stop
CO2 = carbon dioxide
N2O5 = dinitrogen pentoxide (note the a of the
prefix, penta was dropped… However, some
sources, such as the IUPAC Red book
allow the “a” naming the compound as
dinitrogen pentaoxide)
3
3
Name the second species but change the ending to
–IDE … & Stop
Exemplars:
NaCl = sodium chloride
FeO = iron(II) oxide
note there is NO Space between the cation and ( )
CO = carbon monoxide (note that the monowas used for the oxygen only. Note that
the –o- of mono was dropped (the elision
was deleted, but some sources allow its use.
Carbon monooxide can be used (it isn’t often)
But, diiodine is more common (eg in
(Europe) than you might think. p.69 Red Book
http://old.iupac.org/publications/books/rbook/Red_Book_2005.pdf
ICl = iodine monochloride is preferred
Compounds of most Main Group metal ions are
considered to have only a single stable charge and
a roman numeral is not generally be used, unless it
is a compound of gallium indium thallium, tin,
lead or bismuth.
Compounds of Main Group metal ions are
considered to have only a single stable charge and
a roman numeral is not to be used, unless it is
a compound of gallium indium thallium, tin,
lead or bismuth (as mentioned above)
Exemplars:
SiF6 = silicon hexafluoride (note the a of
hexa was kept
When the metal species is a transition metal, Pb, or
Bi, include the oxidation state as a roman numeral.
Technically, the roman numeral is written in ( ) with
no space between the name of the metal cation and
the ( ). This applies to all transition metal cations.
Name the second species:
When the second species is a polyatomic ion,
keep the name in its entirety. Do not change
the ending of the polyatomic ion.
When the second species is a nonmetal monatomic
anion be sure to change the ending to –IDE ..& Stop
Exemplars:
Na2CO3 = sodium carbonate
AgBr = silver(I) bromide or silver bromide
NH4NO3 = ammonium nitrate
ZnCl2 = zinc chloride (Zn is not a transition metal)
NH4Cl =
CrO3 = chromium(VI) oxide
ammonium chloride
Fe(NO3)3 = iron(III) nitrate
FeS2O3 = iron(II) thiosulfate
PbO = lead(II) oxide
Ca3(PO4)2 = calcium phosphate
H2S = hydrogen sulfide is more common but,
dihydrogen sulfide is acceptable
410
Use the flow chart and name each of the following compounds. Ionic compounds and molecular compounds
are mixed freely … thus, you first analyze critically as to the category to which each compound belongs …then
name….
1) ZnS _____________________________________
(is this binary molecular / binary ionic / ternary ionic? … now, apply the rules)
2) Au2S3 ___________________________________
(is this binary molecular / binary ionic / ternary ionic? …. now, apply the rules)
3) OF2 _____________________________________
(is this binary molecular / binary ionic / ternary ionic? …. now, apply the rules)
4) Cr2O3 __________________________________
(is this binary molecular / binary ionic / ternary ionic? …, now apply the rules)
5) N2O ____________________________________
(is this binary molecular / binary ionic / ternary ionic?)
6) Ag2SO4__________________________________
(is this binary molecular / binary ionic / ternary ionic?)
7) SF4____________________________________
These answers are given in reverse
order …just in case you don’t want
to “peek”.
21) dihydrogen oxide
or dihydrogen monoxide
20) zinc phosphate (no roman numeral)
19) iron(III) phosphate
18) aluminum phosphate
(no roman numeral)
17) phosphorus pentachloride
8) MnO2 ____________________________________
9) N2O5 _____________________________________
16) iron(III) chloride
15) titantium(II) nitrate
14) calcium chloride (no r.n)
10) PCl3 ______________________________________
13) nitrogen dioxide
11) NO ______________________________________
12) lead(II) oxide
12) PbO _____________________________________
11) nitrogen oxide or
nitrogen monoxide
13) NO2 _____________________________________
10) phosphorus trichloride
9) dinitrogen pentaoxide
14) CaCl2 ____________________________________
8) manganese(IV) oxide
15) Ti(NO3)2 _________________________________
7) sulfur tetrafluoride
16) FeCl3 ____________________________________
6) silver(I) sulfate or just silver
sulfate
5) dinitrogen oxide
or dinitrogen monoxide
17) PCl5 _____________________________________
18) AlPO4 ___________________________________
19) FePO4 ___________________________________
20) Zn3(PO4)2 _________________________________
21) H2O (technically& with a giggle)_______________________
4) chromium(III) oxide
3) oxygen difluoride
2) gold(III) sulfide
1) zinc sulfide
(no roman numeral)
Now for a laugh… check out: http://www.dhmo.org/facts.html
411
Check your grasp of the strategies for inorganic compound nomenclature
1)
Fact1 : Mn in the compound MnCl4 has an oxidation state of +4
Fact2 : V in the compound VCl4 has an oxidation state of +4
Fact3 : The most correct name for MnCl4 is manganese(IV) chloride
Fact4 : The most correct name for VCl4 is vanadium(IV) chloride
Question: Why do both of the above compound names use a Roman numeral in their name?
* Both metal ions have multiple (more than one) positive oxidation state
____________________________________________________________________________________
2)
Fact1 : Na in the compound Na2SO4 has an oxidation state of +1
Fact2 : Ca in the compound CaSO4 has an oxidation state of +2
Fact3 : The most correct name for Na2SO4 is sodium sulfate
Fact4 : The most correct name for CaSO4 is calcium sulfate
Question: Why do neither of the above compound names contain a Roman numeral in their name?
* Each metal ion has only 1 possible positive oxidation number (neither has multiple positive oxidation states)
____________________________________________________________________________________
3)
Fact1 : Fe in the compound FeCl3 has an oxidation state of +3
Fact2 : Al in the compound AlCl3 has an oxidation state of +3
Fact3 : The most correct name for FeCl3 is iron(III) chloride
Fact4 : The most correct name for AlCl3 is just aluminum chloride
Question: Why does one of the above compound names include a Roman numeral while the name
of the other compound does not include a Roman numeral ?
* The iron has more than one possible positive oxidation state … and aluminum has only one
412
NOMENCLATURE: 1-25 are all ionic compounds. Practice the use of Stock’s system. Twenty six through
thirty one are each molecules, so, use the prefix system to name them. The answers are on the next page.
1) CaO _____________________________
(use PT: do you need to include a Roman numeral ?)
14) NiCO3 _____________________________
(use PT: do you need to include a Roman numeral ?)
2) NiCl3 _____________________________
(use PT: do you need to include a Roman numeral ?)
15) K3PO4 _____________________________
(use PT: do you need to include a Roman numeral ?)
3) CuSO4 _____________________________
(use PT: do you need to include a Roman numeral ?)
16) MnO _____________________________
17) FeO
4) MnO3 _____________________________
(use PT: do you need to include a Roman numeral ?)
5) NaClO _____________________________
_____________________________
18) Li2CO3 ____________________________
19) SnF2
_____________________________
(use PT: do you need to include a Roman numeral ?)
20) HgCl2
_____________________________
6) Sr3(PO4)2 _____________________________
(use PT: do you need to include a Roman numeral ?)
7) AgF _____________________________
(use PT: do you need to include a Roman numeral ?)
21) Ca(OH)2 _____________________________
22) Li2S2O3 ____________________________
23) CuO
_____________________________
8) Au2Te _____________________________
(use PT: do you need to include a Roman numeral ?)
24) Na2SO3 _____________________________
9) PbO2 _____________________________
(use PT: do you need to include a Roman numeral ?)
10) Pb(NO3)4 ____________________________
(use PT: do you need to include a Roman numeral ?)
11) Ca3(PO4)2 __________________________
(use PT: do you need to include a Roman numeral ?)
12) TiO2 _____________________________
(use PT: do you need to include a Roman numeral ?)
13) CrO _____________________________
(use PT: do you need to include a Roman numeral ?)
25) Ni2(Cr2O7)3 ________________________
Naming specific molecules using prefixes
26) NI3 ______________________________
27) SF6_____________________________
28) NO _______________________________
29) SO2 _______________________________
30) OF _______________________________
31) SiO2 ______________________________
413
ANSWERS :
1) calcium oxide (binary, and no Roman numeral is needed,
since calcium has only a single Roman numeral
2) nickel (III) chloride (binary, nickel has at least 2 oxidation
#'s, so you must use a roman numeral. If you assigned
oxidation #'s correctly, you predicted that Ni = +3 state)
3) copper (II) sulfate (ternary : if you assign oxidation #’s
like this:
Cux(SO4)-2
you'll see that X must equal +2. Copper has at
least 2 oxidation #’s so you must use the roman numeral
16)
17)
18)
19)
20)
21)
22)
23)
24)
25)
manganese(II) oxide
iron(II) oxide
lithium carbonate
tin(II) fluoride (stannous fluoride pre-1963 or so)
mercury(II) chloride
calcium hydroxide
lithium thiosulfate
copper(II) oxide
sodium sulfite
nickel(III) dichromate
4) manganese (VI) oxide (binary : assign the
oxidation numbers as such :
MnXO3-2 Mn must equal +6
26) nitrogen triiodide
27) sulfur hexafluoride
28) nitrogen monoxide
29) sulfur dioxide
30) oxygen monofluoride
5) sodium hypochlorite (this is a ternary inorganic)
(ClO)-1 is called "hypochlorite".
31) silicon dioxide (in this case the metalloid, Si,
acts as something like a metal.)
6) strontium phosphate
7) silver fluoride
8) gold(I) telluride
9) lead(IV) oxide
10) lead(IV) nitrate
11) calcium phosphate
12) titantium(IV) oxide
13) chromium(II) oxide
14) nickel(II) carbonate
15) potassium phosphate
414
MORE: Nomenclature: This worksheet is designed to practice the naming of inorganic compounds. Complete
each and every question by providing the most correct answer. You must have your Periodic Table and your
rules for assigning oxidation states, ready.
Name the following using the most correct names.
4) TiO2 ________________________________
14) CrO ___________________________
5) CuNO3 ______________________________
15) CrO3 __________________________
6) Fe(ClO3)2 ___________________________
16) NiS2O3 ________________________
7) Li3PO4 _____________________________
17) Ni2(Cr2O7)3 ___________________
8) NiC2O4 _____________________________
18) Au(NO3)3 ______________________
9) AgNO3 ______________________________
19) ZnO __________________________
10) MnO2 ______________________________
20) HgO __________________________
11) MnO3 ______________________________
21) CaCO3 _________________________
12) Mn2O7 ______________________________
22) Mg(SCN)2 ______________________
13) Cr2O3 ______________________________
Answers:
4) Titanium(IV) oxide
Ti+4 O-2 since Ti has at least 3 possible positive oxidation states, you must use a Roman
numeral to identify the exact nature of the metal ion, for the reader. This allows chemists to differentiate between this
oxide of titanium and the other possible formulations of oxides of titanium, TiO [titanium (II) oxide]
and Ti2O3 [titanium(III) oxide]
5) Copper(I) nitrate
Cu+1 (NO3)-1 since copper has at least two possible positive oxidation states, you must use the
Roman numeral, (I), to differentiate CuNO3 from the other nitrate of copper, which is, copper(II) nitrate [(Cu(NO3)2]
415
6) iron(II) chlorate
Fe+2 (ClO3)-1 since Fe has at least 2 possible positive oxidation states, you must use a Roman
numeral . This allows chemists to differentiate between Fe(ClO3)2 and the other chlorate of iron...... Fe(ClO3)3 , in
which the Fe is in a +3 oxidation state.
Li1+ (PO4)3- Lithium has only a single oxidation value ... so no other formulations of
7) lithium phosphate
phosphates of lithium may exist – so you don’t need to use the Roman numeral – in fact, if you put a Roman
numeral into the name the name is considered to be incorrect.
8) nickel (II) oxalate
9) silver nitrate (no Roman numeral is used)
10) manganese(IV) oxide (must have a roman numeral …. Mn has more than one positive oxidation state)
11) manganese(VI) oxide (must have a roman numeral)
12) manganese(VII) oxide (must have a roman numeral)
13) chromium(III) oxide
(must have a roman numeral)
14) chromium(II) oxide
(must have a roman numeral)
15) chromium(VI) oxide
(must have a roman numeral)
16) nickel(II) thiosulfate (must have a roman numeral)
17) nickel(III) dichromate (must have a roman numeral)
18) gold(III) nitrate
(must have a roman numeral)
19) zinc oxide (No roman numeral is to be used ...it’s wrong if you use one!!!! Zn has only 1 oxid. state)
20) mercury(II) oxide (must have a roman numeral)
21) calcium carbonate (no Roman numeral)
22) magnesium thiocyanate (no Roman numeral)
416