Nomenclature
Name of the coumpounds
-binary compounds (oxides and hydrides)
-ternary compounds(bases, acids and salts)
Valence
Oxidation state
Ionic compounds
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IONS
• Several natural compounds are ionic. That
means that they are formed by IONS.
• IONS are electrized atoms
• In general when there is a positive charge
the ion is called cation, when there is a
negative ion is called anion
The formation of a ionic compound
Coulomb law
The attractive or repulsive force between to
charged points can be calculated by:
q1q2
F = K -------r2
K = dielectric constant depending on
the nature of the medium
Factors that influence the strength of ionic bonding.
The relationship between ions formed and
the nearest noble gas.
Some common monatomic ions of the elements.
Can you see any patterns?
Valence
Valence is a whole number indicating the number
of unpaired electron in an element ready to form
a bond
Na has a lone valence : 1
Conventionally we should write a roman letter aside the
symbol in the round brackets Na(I)
Some elements have more than a valence:
Cr(II); Cr(III); Cr(VI)
Oxidation state
Each atom in a neutral molecule or charged
species is assigned an oxidation number , which
is the virtual charge for a monoatomic ion.
Actually, it is an hypothetical charge assigned to
the atom
assuming that the bonding electrons are
completely held (-) or given away (+) by the
atom
It coincides with the valence as number, but it is
preceded by a sign (+ or -)
Conventional Rules
1) For an atom in its elemental form, the
oxidation state is always zero
H2, Cl2, Zn, Au, N2, Hg, P4, S8 and so
on….oxidation state = 0
Conventional Rules
2) For any monoatomic ion the oxidation
number equals the charge on the ion
F- = -1
K+ = +1
Ca2+ = +2
Al 3+ = +3
S 2- = -2
Conventional Rules
3) Nonmetals usually have negative oxidation numbers,
although they can be positive when bound to more
electronegative elements.
a) Oxygen is usually -2 in both ionic or molecular
compounds. The major exception is in compound
called peroxides, which contain the O22- ion and the
oxidation state is -1.
b) The oxidation number of hydrogen is usually +1 when
bonded to nonmetals and -1 when bonded to metals
c) The oxidation state of fluorine is -1, but the other
halogens can have also positive oxidation state when
combined with oxygen in oxyanions
Conventional Rules
4) The sum of the oxidation number of all
the atoms in a neutral compound is zero.
The sum of the oxidation numbers in a
polyaatomic ion is equal to the charge of
the ion.
Example: the CO3 2- has oxidation number = -2;
H3O+ has oxidation number = +1
Common Monoatomic Ions Common ions are in blue.
Charge
+1
+2
+3
Cations
Formula
Name
H+
Anions
Formula
Name
hydrogen
H-
hydride
Li+
lithium
F-
fluoride
Na+
sodium
Cl-
chloride
K+
potassium
Br-
bromide
Cs+
cesium
I-
iodide
Ag+
silver
Mg2+
magnesium
O2-
oxide
S2-
sulfide
N3-
nitride
Ca2+
calcium
Sr2+
strontium
Ba2+
barium
Zn2+
zinc
Cd2+
cadmium
Al3+
aluminum
Charge
-1
-2
-3
Naming binary ionic compounds
The name of the cation is written first, followed by that of the anion.
The name of the cation is the same as the name of the metal.
Many metal names end in -ium.
The name of the anion takes the root of the nonmetal name
and adds the suffix -ide.
Calcium and bromine form calcium bromide.
Calcium bromide
The rule to follow is that the sum of the oxidation numbers in a neutral
molecule is equal to zero. Between 1 and 2 the minimum common
multiple is 2.
+2 x 1 + -1 x 2 = 0
Ca12+ Br-1
 CaBr2
2
Calcium oxide
The rule to follow is that the sum of the oxidation numbers in a neutral
molecule is equal to zero. Between 2 and 2 the minimum common
multiple is 2.
+2 x 1 + -2 x 1 = 0
Ca12+ O1-2  CaO
Naming Binary Ionic Compounds
PROBLEM: Name the ionic compound formed from the following pairs of
elements:
(a) magnesium and nitrogen
(b) iodine and cadmium
(c) strontium and fluorine
PLAN:
(d) sulfur and cesium
Use the periodic table to decide which element is the metal and
which the nonmetal. The metal (cation) is named first and we
use the -ide suffix on the nonmetal name root.
SOLUTION:
(a) magnesium nitride
(b) cadmium iodide
(c) strontium fluoride
(d) cesium sulfide
Determining Formulas of Binary Ionic Compounds
PROBLEM: Write empirical formulas for the compounds named in Sample
Problem 2.5.
PLAN:
Compounds are neutral. We find the smallest number of each
ion which will produce a neutral formula. Use subscripts to the
right of the element symbol.
SOLUTION:
(a) Mg2+ and N3-; three Mg2+(6+) and two N3-(6-); Mg3N2
(b) Cd2+ and I-; one Cd2+(2+) and two I-(2-); CdI2
(c) Sr2+ and F-; one Sr2+(2+) and two F-(2-); SrF2
(d) Cs+ and S2-; two Cs+(2+) and one S2- (2-); Cs2S
Metals With Several Oxidation States
Element
Copper
Cobalt
Iron
Manganese
Tin
Ion Formula
Systematic Name
Common Name
Cu+1
copper(I)
cuprous
Cu+2
copper(II)
cupric
Co+2
cobalt(II)
Co+3
cobalt (III)
Fe+2
iron(II)
ferrous
Fe+3
iron(III)
ferric
Mn+2
manganese(II)
Mn+3
manganese(III)
Sn+2
tin(II)
stannous
Sn+4
tin(IV)
stannic
Determining Names and Formulas of Ionic
Compounds of Elements That Form More
Than One Ion
PROBLEM: Give the systematic names for the formulas or the formulas for
the names of the following compounds:
PLAN:
(a) tin(II) fluoride
(b) CrI3
(c) ferric oxide
(d) CoS
Compounds are neutral. We find the smallest number of each
ion which will produce a neutral formula. Use subscripts to the
right of the element symbol.
SOLUTION:
(a) Tin (II) is Sn2+; fluoride is F-; so the formula is SnF2.
(b) The anion I is iodide(I-); 3I- means that Cr(chromium) is +3.
CrI3 is chromium(III) iodide
(c) Ferric is a common name for Fe3+; oxide is O2-, therefore the
formula is Fe2O3.
(d) Co is cobalt; the anion S is sulfide(2-); the compound is cobalt
(II) sulfide.
Predicting the Ion and Element Forms
PROBLEM: What monatomic ions do the following elements form?
(a) Iodine (Z = 53)
PLAN:
(b) Calcium (Z = 20)
(c) Aluminum (Z = 13)
Use Z to find the element. Find its relationship to the nearest
noble gas. Elements occurring before the noble gas gain
electrons and elements following lose electrons.
SOLUTION:
I- Iodine is a nonmetal in Group 7A(17). It gains one
electron to have the same number of electrons as 54Xe.
Ca2+ Calcium is a metal in Group 2A(2). It loses two
electrons to have the same number of electrons as 18Ar.
Al3+ Aluminum is a metal in Group 3A(13). It loses three
electrons to have the same number of electrons as 10Ne.
Chemical compounds
There are serveral compounds types. The most
simplest are:
• Oxides (oxygen + another element)
• Hydrides (hydrogen + another element)
• Oxyacids (ternary compounds with a NOT
METAL, oxygen and hydrogen)
• hydroxides (ternary compounds with a METAL,
oxygen and hydrogen)
• Salts (ternary compounds with Metal, a NOT
METAL, and eventually oxygen)
oxides
Oxides have general formula MexOy, or
NMexOy where Me = metal and NMe = not
metal
Examples MexOy : Na2O, Li2O, K2O, CaO,
MgO, BaO…..
Examples NMezOt : SO3, CO2, P2O5, Cl2O,
N2O5……..
Basic Oxides
4Na(s) + O2 (g) => 2Na2O (s)
Ca(s) + O2 (g) => CaO (s)
4Fe(s) + 3O2 (g) => 2Fe2O3 (s)
2Fe(s) + O2 (g) => 2FeO (s)
4Al(s) + 3O2 (g) => 2Al2O3 (s)
4Cr(s) + 3O2 (g) => 2Cr2O3 (s)
2Cr(s) + O2 (g) => 2CrO (s)
2Mn(s) + O2 (g) => 2MnO (s)
manganese(II) oxide
2Hg(s) + O2 (g) => 2HgO (s)
4Hg(s) + O2 (g) => 2Hg2O (s)
2Zn(s) + O2 (g) => 2ZnO (s)
4Cu(s) + O2 (g) => 2Cu2O (s)
2Cu(s) + O2 (g) => 2CuO (s)
sodium oxide
calcium oxide
ferric oxide or iron(III)oxide
ferrous oxide or iron(II)oxide
dialluminium trioxide (amphoteric)
dichromium trioxide
monochromium monoxide
monomanganese
monoxide
mercuric oxide or mercury(II)oxide
mercurous oxide or mercury(I)oxide
zinc oxide
cupric oxide or copper(II) oxide
cuprous oxide or copper(I) oxide
or
Acidic Oxides
S8(g) + 8O2 (g) => 8SO2 (g)
sulfur dioxide or sulfurous anydride or
sulfur(IV) oxide
S8(g) + 12O2 (g) => 8SO3 (g)
sulfur trioxide or sulfuric anydride or
sulfur(VI) oxide
C(s) + O2 (g) => CO2 (g)
carbon dioxide or carbonic anydride
2N2(g) + 3O2 (g) => 2N2O3(g) dinitrogentrioxide or nitrous anydride
or nitrogen(III) oxide
2N2(g) + 5O2 (g) => 2N2O5(g) dinitrogenpentaoxide or nitric anydride
or nitrogen(V) oxide
P4(s) + O2 (g) => 2P2O (g)
diphosphorousmonooxide
or
hypophosphorous anydride or phosphorous(I) oxide
P4(s) + 3O2 (g) => 2P2O3 (g)
diphosphoroustrioxide or phosphorous
anydride or phosphorous(III) oxide
P4(s) + 3O2 (g) => 2P2O5 (g)
diphosphorouspentaoxide
or
phosphoric anydride or phosphorous(V) oxide
Acidic Oxides
2Mn(s) + 2O2 (g) => 2MnO2 (g) manganese dioxide or manganous
anydride or manganese(IV) oxide (Mn4+ amphoteric)
2Mn(s) + 3O2 (g) => 2MnO3 (g) manganese trioxide or manganic
anydride or manganese(VI) oxide
4Mn(s) + 7O2 (g) => 2Mn2O7 (g) dimanganese
eptaoxide
or
permanganic anydride or manganese(VII) oxide
4Cr(s) + 3O2 (g) => 2Cr2O3 (g) dichromium trioxide or chromous
anydride or hromium(III) oxide (Cr3+ amphoteric)
2Cr(s) + 3O2 (g) => 2CrO3 (g) chromium trioxide or chromic anydride
or chromium(VI) oxide
2Sn(s) + O2 (g) => 2SnO (g)
tin monoxide or stannous anydride or
tin(II) oxide (Sn2+ amphoteric)
2Sn(s) + 2O2 (g) => 2SnO2 (g) tin dioxide or stannic anydride or
tin(IV) oxide
4Al(s) + 3O2 (g) => 2Al2O3 (s) dialluminium trioxide (amphoteric)
Hydrides
Hydrides have general formula MexHy, o HyNMex dove Me
= metal e NMe = non metal
Metal hydrides MexHy : NaH, CaH2, FeH3, KH
Sodium hydride, calcium hydride, ferric hydride, potassium
hydride
Hydracids HxNMez : HCl, H2S, HBr, HF, HI, HCN.
Hydrochloric acid, hydrogen sulfide, hydrobromic acid,
hydrifluoric acid, hydroiodic acid, hydrogen cyanide
Covalent hydrides : H2O, NH3, PH3, SbH3, CH4.
Hydrogen oxide (water), Nitrane (ammonia), phosphane,
stibane, carbane (methane)
Oxyacids
General formula HxNMeyOz and easily lose H+:
HNO3 (nitric), H2SO4 (sulforic), H2CO3 (carbonic),
HClO (Hypoclorous), H3PO4(orthophosphoric),
HPO3 (metaphosphoric), H2SO3 (sulfurous)……
Acids can lose hydrogen as H+ then acid radical
can be formed (polioxoanions)
NO3- (nitrate), SO42- (sulphate), CO32- (carbonate),
ClO- (hypochlorite), PO43- (ortophosphato), PO3(metaphosphato), SO32-(sulphite),…..
Oxyacids
SO2 (g) + H2O(l) => H2SO3 (aq) sulfurous acid, triossisulfuric acid
SO3 (g) + H2O(l) => H2SO3 (aq) sulfuric acid, tetraossisulfuric acid
CO2 (g) + H2O(l) => H2CO3 (aq) carbonic acid, triossicarbonic acid
N2O3(g) + H2O(l) => 2HNO2 (aq) nitrous acid, diossinitric acid
N2O5(g) + H2O(l) => 2HNO3 (aq) nitric acid, Triossinitric acid
Oxyacids
P2O(g) + 3H2O(l) => 2H3PO2 (aq) hypophosphorous acid,
P2O3(g) + 3H2O(l) => 2H3PO3 (aq) (ortho)phosphorous acid
P2O5(g)+H2O(l)=> 2HPO3(aq) metaphosphoric acid,
P2O5(g)+2H2O(l)=> 2H4P2O7(aq) pyrophosphoric acid,
P2O5(g)+3H2O(l)=> 2H3PO4(aq) orthophosphoric acid,
Oxyacids
Cl2O (g) + H2O(l) => 2HClO (aq) hypochlorous acid, monooxi chloric
acid
Cl2O3 (g) + H2O(l) => 2HClO2 (aq) chlorous acid, dioxi chloric acid
Cl2O5 (g) + H2O(l) => 2HClO3 (aq) chloric acid, trioxi chloric acid
Cl2O7 (g) + H2O(l) => 2HClO4 (aq) perchloric acid, tetraoxi chloric acid
Oxyacids
P2O(g) + 3H2O(l) => 2H3PO2 (aq) hypophosphorous acid,
P2O3(g) + 3H2O(l) => 2H3PO3 (aq) (ortho)phosphorous acid
P2O5(g)+H2O(l)=> 2HPO3(aq) metaphosphoric acid,
P2O5(g)+2H2O(l)=> 2H4P2O7(aq) pyrophosphoric acid, (P2O7)4- pyrophosphate
P2O5(g)+3H2O(l)=> 2H3PO4(aq) orthophosphoric acid, (PO4)3- orthophosphate
Phosphate in biology
Phosphate minerals
Turquoise
CuAl6(PO4)4(OH)8·4H2O
Crystals of struvite from dog urine
NH4MgPO4·6H2O
Fluoroapatite
Ca5(PO4)3F
Amblygonite
(Li,Na)AlPO4(F,OH)
Environmental Impact of phosphate
Phosphate will stimulate the growth of plankton and aquatic plants which provide
food for larger organisms, including zooplankton, fish, humans, and other
mammals. Plankton represents the base of the food chain. Initially, this increased
productivity will cause an increase in the fish population and overall biological
diversity of the system. But as the phosphate loading continues and there is a buildup of phosphate in the lake or surface water ecosystem, the aging process of lake or
surface water ecosystem will be accelerated. The overproduction of lake or water
body can lead to an imbalance in the nutrient and material cycling process (Ricklefs,
1993). Eutrophication (from the Greek - meaning "well nourished") is enhanced
production of primary producers resulting in reduced stability of the ecosystem
ThioOxyacids
These acids occur when sulfur
substitutes the oxygen with oxidation
number equal to -2.
Sulfur oxyacids
Sulfate minerals
Barite
BaSO4
Celestite, SrSO4
Chalcantite , CuSO4 x 5H2O
Anydrite, CaSO4
Some Common Polyatomic Ions
Formula
Name
Formula
Name
H3O+
hydronium
Cations
NH4
+
ammonium
Common Anions
CH3COO-
acetate
CO3-2
carbonate
CN-
cyanide
CrO4-2
chromate
OH-
hydroxide
Cr2O7-2
dichromate
ClO3-
chlorate
O2-2
oxide
NO2NO -
nitrite
SO4-2
sulfate
nitrate
PO4-3
phosphate
MnO4-
permanganate
3
Carboxylic acids
Hydroxides
The general formula is Me(OH)n where n is
the metal valence, in acqueous solution
they easily lose OH- ions.
NaOH, Mg(OH)2, Fe(OH)3, Al(OH)3, KOH;
Ca(OH)2………
In solution they exist as metal cations and
OH- ions
Na+, Mg 2+, Fe3+, Al3+, K+, Ca 2+….
Salts
Salts are derivatives originated by the combination of metal oxides and
non metal oxides. In water, neutralization reactions between
oxyacids and hydroxides. Salts are made of metal cations and
anions, basically an acid radical. They are ionic compounds. In
water solution they easily dissociate in Men+, and acid radicals
(NMeyOz)t- or (NMe)t-.
NaCl => Na+ + ClCaCO3=> Ca2+ + CO32Na2SO4 => 2Na+ + SO42Ca(ClO)2 => Ca 2+ + 2 ClOKNO3 => K+ + NO3-
Salts
NaOH(aq) + HCl (aq)=> NaCl (aq)
sodium chloride=> Na+ + ClCa(OH)2 (aq)+ CO2 (g)=> CaCO3 (aq)
calcium carbonate+ H2O=> Ca2+ + CO32Na2O (s) + H2SO4 (aq)=> Na2SO4 (aq)
sodium sulfate+ H2O => 2Na+ + SO42Ca(OH)2 (aq)+ HClO (aq)=> Ca(ClO)2 (aq)
calcium hypochlorite+ H2O => Ca 2+ + 2 ClOKOH(aq) + HNO3 (aq)=> KNO3 (aq)
potassium nitrate+ H2O => K+ + NO3-
Acid Salts
Ca(OH)2 (aq)+ 2H2CO3 (g)=> Ca(HCO3)2 (aq)
calcium bicarbonate or monohydrogen carbonate+ 2H2O=> Ca2+
+ 2HCO3Ca(OH)2 (aq)+ H2CO3 (g)=> CaCO3 (aq)
calcium carbonate + 2H2O
Na(OH) (aq)+ H2SO4 (g)=> Na(HSO4) (aq
sodium bisulfate or monohydrogen sulfate+ H2O
2Na(OH) (aq)+ H2SO4 (g)=> Na2SO4 (aqsodium sulfate + 2H2O
Basic Salts
Al(OH)3 (aq)+ 2H2CO3 (g)=> Al(OH)(CO3) (aq) alluminium
monohydroxicarbonate+ 2H2O
Sn(OH)2 (aq)+ HNO3 (g)=> Sn(OH)NO3 (aq) stannous or Tin(II)
monohydroxi nitrate+ H2O
Mn(OH)2 (aq)+ HNO3 (g)=> Mn(OH)(NO3) (aq manganous or
Mangenese(II) monohydroxinitrate + H2O
2Cu(OH)2 (aq)+ HCl (g)=> Cu(OH)Cl (aq cupric or Copper(II)
monohydroxi chloride+ H2O
Naming oxoanions
Root
Suffixes
per
root
ate
ClO4-
perchlorate
root
ate
ClO3-
chlorate
root
ite
ClO2-
chlorite
root
ite
ClO-
hypochlorite
No. of O atoms
Prefixes
hypo
Examples
Table 2.6
Numerical Prefixes for Hydrates and Binary Covalent Compounds
Number
Prefix
Number
Prefix
Number
Prefix
1
mono
4
tetra
8
octa
2
di
5
penta
9
nona
3
tri
6
hexa
7
hepta
Element group
6
Element (central
atom)
Chromium
Oxidation
Acid formula
state
Acid name[8][9]
Anion
formula
Anion name
H2CrO4
Chromic acid
CrO42−
Chromate
H2Cr2O7
Dichromic acid
+7
HMnO4
Permanganic acid
+6
H2MnO3
Manganic acid
+7
HTcO4
Pertechnetic acid
+5
HTcO3
Technetic acid
+7
HReO4
Perrhenic acid
+5
HReO3
Rhenic acid
H3BO3
Boric acid
(formerly orthoboric acid)[10]
(HBO2)n
Metaboric acid
+6
Cr2O72−
MnO4−
Dichromate
Permanganate
Manganese
7
MnO32−
TcO4−
Manganate
Pertechnetate
Technetium
TcO3−
ReO4−
Technetate
Perrhenate
Rhenium
13
Boron
ReO3−
BO33−
Rhenate
Borate
(formerly orthoborate)
+3
BO2−
Metaborate
Carbon
+4
14
Silicon
CO32−
H2CO3
Carbonic acid
H4SiO4
Silicic acid
SiO44−
(formerly orthosilicic acid)[10]
H2SiO3
Metasilicic acid
HOCN
Cyanic acid
HNCO
Isocyanic acid
HONC
Fulminic acid
HNO3
Nitric acid
HNO4
Peroxynitric acid
HNO2
Nitrous acid
HOONO
Peroxynitrous acid
H2NO2
Nitroxylic acid
Carbonate
Silicate (formerly orthosilicate)
+4
14, 15 Carbon, nitrogen +4, −3
SiO32−
OCN−
NCO−
ONC−
NO3−
Metasilicate
Cyanate
Isocyanate
Fulminate
Nitrate
+5
15
Nitrogen
NO4−
NO2−
Peroxynitrate
Nitrite
+3
+2
OONO−
NO22−
Peroxynitrite
Nitroxylate
+1
N2O22−
H2N2O2
Hyponitrous acid
H3PO4
Phosphoric acid
PO43−
(formerly orthophosphoric acid)[10]
PO3−
HPO3
Metaphosphoric acid
H4P2O7
Pyrophosphoric acid
(diphosphoric acid)
H3PO5
Peroxomonophosphoric acid
+5, +3
(HO)2POPO(OH)2
Diphosphoric(III,V) acid
O2POPOO2−2
+4
(HO)2OPPO(OH)2
Hypophosphoric acid
(diphosphoric(IV) acid)
O2OPPOO24−
Nitrogen 15th group
Orthophosphoric acid= tetraoxyphosphoric acid
Metaphosphoric acid = dioxyphosphoric acid
Pyrophospric acid = eptaphosphoric acid
+5
P2O74−
PO33−
PHO32−
H2PHO3
Phosphonic acid
H2P2H2O5
Diphosphonic acid
P2H2O5−3
+1
HPH2O2
Phosphinic acid
PH2O2−
+5
H3AsO4
Arsenic acid
Phosphoros 15th group
+3
AsO43−
Arsenic 15th group
+3
H3AsO3
Arsenous acid
H2SO4
Sulfuric acid
H2S2O7
Disulfuric acid
H2SO5
Peroxomonosulfuric acid
AsO33−
SO42−
S2O72−
Arsenite
Arsenic 15th group
Sulfate
Sufur 16th group
Disulfate
+6
H2S2O8
Peroxodisulfuric acid
+5
H2S2O6
Dithionic acid
+5, 0
H2SxO5
Polythionic acids
(x = 3, 4…)
H2SO3
Sulfurous acid
H2S2O5
Disulfurous acid
+4, 0
H2S2O3
Thiosulfuric acid
+3
H2S2O4
Dithionous acid
SO52−
S2O82−
S2O62−
SxO52−
SO32−
Peroxomonosulfate
Peroxodisulfate
Dithionate
Polythionates
Sulfite
+4
S2O52−
S2O32−
S2O42−
Disulfite
Thiosulfate
Dithionite
Sulforic acid= tetraoxysulforic acid
Sulfurous acid = trioxysulforic acid
+3, −1
H2S2O2
Thiosulfurous acid
+2
H2SO2
Sulfoxylic acid
+6
H2SeO4
Selenic acid
+4
H2SeO3
Selenous acid
H2TeO4
Telluric acid
S2O22−
SO22−
SeO42−
SeO32−
TeO42−
Thiosulfite
Sufur 16th group
Sulfoxylate
Selenate
Selenium16th group
Selenite
Tellurate
tellurium 16th group
+6
H6TeO6
Orthotelluric acid
+4
H2TeO3
Tellurous acid
+7
HClO4
Perchloric acid
+5
HClO3
Chloric acid
TeO66−
TeO32−
ClO4−
ClO3−
Orthotellurate
Tellurite
Perchlorate
Chlorate
chlorine 17th group
+3
HClO2
Chlorous acid
+1
HClO
Hypochlorous acid
ClO2−
ClO−
Chlorite
Hypochlorite
+7
HBrO4
Perbromic acid
+5
HBrO3
Bromic acid
+3
HBrO2
Bromous acid
+1
HBrO
Hypobromous acid
HIO4
Periodic acid
H5IO6
Orthoperiodic acid
+5
HIO3
Iodic acid
+1
HIO
Hypoiodous acid
BrO4−
BrO3−
Perbromate
Bromate
bromine 17th group
Bromine
BrO2−
BrO−
IO4−
Bromite
Hypobromite
Periodate
+7
IO65−
Orthoperiodate
Iodine
IO3−
IO−
Iodate
Hypoiodite
iodine 17th group
Determining Names and Formulas of Ionic
Compounds Containing Polyatomic Ions
PROBLEM: Give the systematic names or the formula or the formulas for the
names of the following compounds:
(a) Fe(ClO4)2
PLAN:
(b) sodium sulfite
(c) Ba(OH)2 8H2O
Note that polyatomic ions have an overall charge so when
writing a formula with more than one polyatomic unit, place the
ion in a set of parentheses.
SOLUTION:
(a) ClO4- is perchlorate; iron must have a 2+ charge. This is
iron(II) perchlorate.
(b) The anion sulfite is SO32- therefore you need 2 sodiums per
sulfite. The formula is Na2SO3.
(c) Hydroxide is OH- and barium is a 2+ ion. When water is
included in the formula, we use the term “hydrate” and a prefix
which indicates the number of waters. So it is barium hydroxide
octahydrate.
Recognizing Incorrect Names and Formulas
of Ionic Compounds
PROBLEM: Something is wrong with the second part of each statement.
Provide the correct name or formula.
(a) Ba(C2H3O2)2 is called barium diacetate.
(b) Sodium sulfide has the formula (Na)2SO3.
(c) Iron(II) sulfate has the formula Fe2(SO4)3.
(d) Cesium carbonate has the formula Cs2(CO3).
SOLUTION: (a) Barium is always a +2 ion and acetate is -1. The “di-” is
unnecessary.
(b) An ion of a single element does not need parentheses.
Sulfide is S2-, not SO32-. The correct formula is Na2S.
(c) Since sulfate has a 2- charge, only 1 Fe2+ is needed. The
formula should be FeSO4.
(d) The parentheses are unnecessary. The correct formula is
Cs2CO3.
Naming Acids
1) Binary acids solutions form when certain gaseous compounds
dissolve in water.
For example, when gaseous hydrogen chloride(HCl) dissolves in
water, it forms a solution called hydrochloric acid. Prefix hydro- +
anion nonmetal root + suffix -ic + the word acid - hydrochloric acid
2) Oxoacid names are similar to those of the oxoanions, except for
two suffix changes:
Anion “-ate” suffix becomes an “-ic” suffix in the acid. Anion “-ite”
suffix becomes an “-ous” suffix in the acid.
The oxoanion prefixes “hypo-” and “per-” are retained. Thus, BrO4is perbromate, and HBrO4 is perbromic acid; IO2- is iodite, and
HIO2 is iodous acid.
Determining Names and Formulas of the
following anions
PROBLEM: Name the following anions and give the names and formulas of
the acids derived from them:
(a) Br -
(b) IO3 -
(c) CN -
(d) SO4 2-
(e) NO2 -
SOLUTION:
(a) The anion is bromide; the acid is hydrobromic acid, HBr.
(b) The anion is iodate; the acid is iodic acid, HIO3.
(c) The anion is cyanide; the acid is hydrocyanic acid, HCN.
(d) The anion is sulfate; the acid is sulfuric acid, H2SO4.
(e) The anion is nitrite; the acid is nitrous acid, HNO2.
Determining Names and Formulas of Binary
Covalent Compounds
PROBLEM:
(a) What is the formula of carbon disulfide?
(b) What is the name of PCl5?
(c) Give the name and formula of the compound whose
molecules each consist of two N atoms and four O atoms.
SOLUTION: (a) Carbon is C, sulfide is sulfur S and di-means 2 - CS2.
(b) P is phosphorous, Cl is chloride, the prefix for 5 is penta-.
Phosphorous pentachloride.
(c) N is nitrogen and is in a lower group number than O (oxygen).
Therefore the formula is N2O4 - dinitrogen tetraoxide.
Recognizing Incorrect Names and Formulas
of Binary Covalent Compounds
PROBLEM:
Explain what is wrong with the name of formula in the second
part of each statement and correct it:
(a) SF4 is monosulfur pentafluoride.
(b) Dichlorine heptaoxide is Cl2O6.
(c) N2O3 is dinitrotrioxide.
SOLUTION: (a) The prefix mono- is not needed for one atom; the prefix for
four is tetra-. So the name is sulfur tetrafluoride.
(b) Hepta- means 7; the formula should be Cl2O7.
(c) The first element is given its elemental name so this is
dinitrogen trioxide.
Calculating the Molecular Mass of a Compound
PROBLEM:
Using the data in the periodic table, calculate the molecular (or
formula) mass of the following compounds:
(a) tetraphosphorous trisulfide
PLAN:
SOLUTION:
(b) ammonium nitrate
Write the formula and then multiply the number of atoms(in the
subscript) by the respective atomic masses. Add the masses for
the compound.
(a) P4S3
molecular = (4xatomic mass of P)
mass
+ (3xatomic mass of S)
(b) NH4NO3
molecular = (2xatomic mass of N)
mass
+ (4xatomic mass of H)
= (4x30.97amu) + (3x32.07amu)
= 220.09amu
+ (3xatomic mass of O)
= (2x14.01amu)+ (4x1.008amu) +
(3x16.00amu)
= 80.05amu
Naming Compounds from Their Depictions
PROBLEM:
Each box contains a representation of a binary compound.
Determine its formula, name, and molecular (formula) mass.
(a)
SOLUTION:
(a) There is 1 sodium (brown) for every fluorine (green), so the
formula is NaF.
formula mass =
(1x atomic mass of Na) +
=
(1x atomic mass of F)
22.99 amu + 19.00 amu = 41.99 amu
(b) There are 3 fluorines (green) for every nitrogen (blue), so the
formula is NF3.
molecular mass =
=
(3x atomic mass of F)
(1x atomic mass of N)
(3x 19.00 amu) + 14.01 amu = 71.01 amu
Determining Names and Formulas of Ionic
Compounds Containing Polyatomic Ions
PROBLEM: Give the systematic names or the formula or the formulas for the
names of the following compounds:
(a) Fe(ClO4)2
PLAN:
(b) sodium sulfite
(c) Ba(OH)2 8H2O
Note that polyatomic ions have an overall charge so when
writing a formula with more than one polyatomic unit, place the
ion in a set of parentheses.
SOLUTION:
(a) ClO4- is perchlorate; iron must have a 2+ charge. This is
iron(II) perchlorate.
(b) The anion sulfite is SO32- therefore you need 2 sodiums per
sulfite. The formula is Na2SO3.
(c) Hydroxide is OH- and barium is a 2+ ion. When water is
included in the formula, we use the term “hydrate” and a prefix
which indicates the number of waters. So it is barium hydroxide
octahydrate.
Recognizing Incorrect Names and Fromulas
of Ionic Compounds
PROBLEM: Something is wrong with the second part of each statement.
Provide the correct name or formula.
(a) Ba(C2H3O2)2 is called barium diacetate.
(b) Sodium sulfide has the formula (Na)2SO3.
(c) Iron(II) sulfate has the formula Fe2(SO4)3.
(d) Cesium carbonate has the formula Cs2(CO3).
SOLUTION: (a) Barium is always a +2 ion and acetate is -1. The “di-” is
unnecessary.
(b) An ion of a single element does not need parentheses.
Sulfide is S2-, not SO32-. The correct formula is Na2S.
(c) Since sulfate has a 2- charge, only 1 Fe2+ is needed. The
formula should be FeSO4.
(d) The parentheses are unnecessary. The correct formula is
Cs2CO3.
Naming Compounds
PROBLEM:
Using the data in the periodic table, name the following
compounds:
(a) Ca3(PO4)2
(b) PH3
PLAN:
Recognize to which class of compounds they belong and recall
the nomenclature’s rules.
SOLUTION: (a) Ca3(PO4)2
It is a salt. The cation is Ca2+, as the calcium belongs to the second group.
The acid has as radical the (PO4)3-. The corresponding acid is H3PO4. The
oxidation number of P is +5, it is the highest. Phosphoric acid is the name of
the acid, corresponding to Phosphate as anion. Calcium Phosphate is the
name
(b) PH3
This compound is a binary compound made of a non metal and an hydride.
The root comes from the non metal, Phosph and the suffix is ane.
Phosphane.
Formula of Compounds
PROBLEM:
Using the data in the periodic table, name the following
compounds:
(a) Berillium hydrogen sulfate
(b) Cupric sulfide
PLAN:
Recognize to which class of compounds they belong and recall
the nomenclature’s rules..
SOLUTION: (a) Berillium hydrogen sulfate
It is a salt. The cation is Be2+, as the berillium belongs to the second group.
The name hydrogen sulfate mean it comes from the sulfuric acid, where the
sulfur as the highest oxidation number, +6. SO3 + H2O = H2SO4, sulfuric acid.
Monohydrogen means that one hydrogen is left. Be(HSO4)2
(b) Cupric sulfide
This compound is a binary compound, made of a non metal and a metal. It is a
salt. The cation is copper in the highest oxidation number +2. Sulfide comes
from sulfidric acid or hydrogen sulfide, where the S has -2 as oxidation
number. H2S is the acid and S2- is the anion. CuS is the salt