Lecture outline: Chapter 21. Atomic structure2. The Periodic Table3. Molecules and ions4 Naming ionic and molecular compounds4. Naming ionic and molecular compounds
S. Ensign, Atomic structure & nomenclature1
~400 B C400 B.C.
Can matter be divided endlessly into smaller and smaller pieces or and smaller pieces, or is there a point at is there a point at which it can’t be
S. Ensign, Atomic structure & nomenclature2
divided anymore??
The Atomic Theory of Matter• John Dalton:
Each element is composed of atoms–Each element is composed of atoms–All atoms of an element are identical.–In chemical reactions, the atoms are
not changed Pb + Snot changed.–Compounds are formed when atoms
f th l t bi
Pb + S
of more than one element combine.
S. Ensign, Atomic structure & nomenclature3
Dalton’s law of multiple proportionsAtoms join together in small whole number ratios to make compoundsnumber ratios to make compounds
OHH
C OO H NH
CH
HH CH
HH OO C OO H NH
CH
HH CH
HH O
Atoms can combine in different ratios to make different compoundsratios to make different compounds
OHH
O HH O H NH
NH
NH
S. Ensign, Atomic structure & nomenclature4
O O HH O H NH
NH
NH
Atoms of element 1
Atoms of l t 2
Compounds of l t 1 d 2
Mixture of l t 1 d 2element 1 element 2 elements 1 and 2 elements 1 and 2
OH
OH O
HHO
H HO O
O
HH
H
O OH H
O
O HOO
HH
H H
O
OH
HH
OHH
S. Ensign, Atomic structure & nomenclature5
Observations/studies of two phenomena were key to determiningphenomena were key to determining
the structure of the atom • Electricity
Separable charges are associated with matter
• RadioactivitySeparable charges are associated with matter
y
Atoms are composed of subatomic particles
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Atoms are composed of subatomic particles
Three types of radiation emitted from radioactive uraniumradioactive uranium
(-) α particle+2(-)
(+)γ ray
(+) β particleUranium source
-1
Electrically h d Detector
S. Ensign, Atomic structure & nomenclature7
charged plates
Detector
Fun household sources of radioactivityFi t ( i k 1970 d li ) th• Fiestaware (cirka 1970 and earlier): the orange color comes from uranium salts
• Lantern mantles (Thorium)
S. Ensign, Atomic structure & nomenclature8
• Smoke detectors (Americium)
Atomic Structure: components of the atom
electrons Charge: -1.60 x 10-19 C “(-1)”Mass: 9.109 x 10-28 g
protons: found in the nucleus, they have a positive charge equal in magnitude to thepositive charge equal in magnitude to the electron’s negative charge.
Charge: +1 60 x 10-19 C “(+1)”
neutrons: found in the nucleus virtually
Charge: +1.60 x 10 C (+1)Mass: 1.673 x 10-24 g
neutrons: found in the nucleus, virtually same mass as a proton but no charge.
Charge: neutral
S. Ensign, Atomic structure & nomenclature9
gMass: 1.675 x 10-24 g
Atomic structureWhat are the subatomic particles how big• What are the subatomic particles, how big are they, and how massive are they?
• How do the subatomic particles associate in atoms?
• Plum pudding model: (incorrect)
S. Ensign, Atomic structure & nomenclature10
The Rutherford experiment
+2+2+2+2+2+2+2+2+2+2+2+2+2+2+2+2+2+2+2
Alpha particle source Thin gold sheet
S. Ensign, Atomic structure & nomenclature11
Detector
Interpretation of Rutherford’s of Rutherford s experiment
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The atom is mostly empty space, with the majority of the mass concentrated in a small, dense region
Nucleus (proton(s) and neutron(s)~10-18 cm
electron: “orbits” the nucleuselectron: orbits the nucleus
“multielectron atoms” have more than one e- “orbiting” the nucleus
10 13
S. Ensign, Atomic structure & nomenclature13
~10-13 cm
Diameter of atom ~ 10-8 cm (~1-5 Å)
The electron is ~1000 times smaller in size than the proton, but occupies a space ~10,000-100,000 times
greater than the size of the nucleus
Golf ball nucleus on 50 yard line(2 cm diameter)
The stadium ( 200 m diameter) represents the space in which the electron(s) reside!
S. Ensign, Atomic structure & nomenclature14
electron(s) reside!
How small is an atom???
Density of a nucleus?Density of a nucleus?Nucleus (proton(s) and neutron(s)
p+
p+np+
n
electron: “orbits” the nucleus
p
n
p+p+
n
S. Ensign, Atomic structure & nomenclature15
Like forces repel, opposites attract, so…
What holds the nucleus together?
Why don’t the electrons fall into the nucleus??nucleus??
Nucleus (proton(s) and neutron(s)Nucleus (proton(s) and neutron(s)
p+nn
electron: “orbits” the nucleus
S. Ensign, Atomic structure & nomenclature16
p+
n
p+n
p+n
Four basic attractive forces in natureFour basic attractive forces in nature
• Gravitational (masses)
Ma Gravitational (masses)
• Electromagnetic (electrically charged and/or magnetized)
agnitude o and/or magnetized)• Weak nuclear force
S f
of force inc
• Strong nuclear force
creases
p+
p+np+
n
p+n
S. Ensign, Atomic structure & nomenclature17
nn
What defines the atoms of a What f n s th atoms of a single element?
If all atoms consists of protons, neutrons, and electrons, then what makes oxygen oxygen and carbon carbon?
S. Ensign, Atomic structure & nomenclature18
Elements are classified on the basis of the number of protons in the nucleusnucleus
All t f i l t h thAll atoms of a given element have the same number of protons in the nucleus
Z= atomic number = # of protons in pthe nucleus
S. Ensign, Atomic structure & nomenclature19
Elements are classified on the basis of the number of protons in the nucleus
All atoms of a given element have the same number of protons in the nucleus
f p
Z= atomic number = # of protons in the nucleus
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How many neutrons and electrons i i ?in a given atom?
• # e- = # p+# e = # p• # neutrons can vary
(# + # ) #• Σ (# p+ + # n) = mass #
S. Ensign, Atomic structure & nomenclature21
Atomic Symbols
X ← Element SymbolAMass number →
X ← Element Symbol
ZAtomic number →
39 K ← Element Symbol39Mass number →
K y
19Atomic number →
S. Ensign, Atomic structure & nomenclature22
Isotopes: atoms of an element that differ in the number of neutrons in thediffer in the number of neutrons in the nucleus
Isotopes have the same atomic pnumber but different mass numbers
S. Ensign, Atomic structure & nomenclature23
Two isotopes of carbon
p+
p+ nn p+
np+
p+p+nn
Carbon-12p+
p+ nn p+
np+
p+p+nn
Carbon-13n
n p+p+ n p+p+
6 protons6 neutrons
6 protons7 neutrons7 neutrons
12 136
12C 613C
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Hydrogen, the simplest element
S. Ensign, Atomic structure & nomenclature25
Silver has two isotopes: one with 60 ne trons one ith 62 ne trons Whatneutrons, one with 62 neutrons. What are the mass numbers and symbols of these isotopes?
For silver (Ag), Z = 47( g),
S. Ensign, Atomic structure & nomenclature26
Give the complete symbol for each of the following atoms
ZAX
for each of the following atoms
Sodium with 12 neutronsSodium with 12 neutrons
argon with 21 neutronsFor Na, Z = 11
argon with 21 neutrons
Gallium with 39 neutronsFor Ar, Z = 18
Gallium with 39 neutronsFor Ga, Z = 31
S. Ensign, Atomic structure & nomenclature27
How many e- p+ and n are present inHow many e , p and n are present in an atom of:
40Ca See the Periodic
119SnTable to find the atomic numbers for
244Pthese elements
244Pu
S. Ensign, Atomic structure & nomenclature28
Complete the following table using the Periodic Table and the information provided
Symbol 46Ti 127TeSymbol Ti Te
# protons 45
# neutrons 58 18
Atomic # 16 38
Mass # 88
S. Ensign, Atomic structure & nomenclature29
What is the origin of the name of the “uncola” beverage “7 up”?uncola beverage 7 up ?
S. Ensign, Atomic structure & nomenclature30
Atomic weights: We will cover this material in lecture 7material in lecture 7
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The Periodic Table
S. Ensign, Atomic structure & nomenclature32
The Periodic Table
S. Ensign, Atomic structure & nomenclature33
The Periodic TableHorizontal rows = “periods” n = 1,2,3,4,5,6,7
n = 1
n = 2n = 3
n = 4n = 5n 5n = 6
n = 7n = 7
n = 6
S. Ensign, Atomic structure & nomenclature34
n = 7
The Periodic Tablevertical columns = “families” or “groups”vertical columns families or groups
n = 1
n = 2n = 3
n = 4n = 5n 5n = 6
n = 7n = 7
n = 6
S. Ensign, Atomic structure & nomenclature35
n = 7
The Periodic TableMetals, metalloids, and nonmetals
S. Ensign, Atomic structure & nomenclature36
The Periodic TableSome important group names
Alka
met
Alka
met
hal
Nob
gaslials
aline earthtals
ogens
ble ses
The transition metals
S. Ensign, Atomic structure & nomenclature37
Elements within groups (families) have similar chemical propertiessimilar chemical properties
S. Ensign, Atomic structure & nomenclature38
Elements within groups (families) have similar chemical propertiessimilar chemical properties
Chemical properties of alkali metals:• react vigorously with water to produce hydrogen gas•React vigorously with oxygen to produce metal hydroxides•React vigorously with oxygen to produce metal hydroxides•React vigorously with halogens to produce saltsPhysical properties of alkali metals:•Soft metal•Silver-colored•Low density•Low melting and boiling points
S. Ensign, Atomic structure & nomenclature39
Elements Essential for LifeElements Essential for Life
S. Ensign, Atomic structure & nomenclature40
Molecular and ionic compoundsMolecular and ionic compounds•114 elements by themselves = ~114 substances (yawn)
•“Glue” different elements together in gdifferent ratios infinite number of potentially interesting compounds!!
S. Ensign, Atomic structure & nomenclature41
A molecule (molecular compound; covalent compound)covalent compound)
An assembly of two or more nonmetalyatoms, tightly bound (bonded) together
•Molecules of a single atom
•Molecules of more than one type of atomyp
S. Ensign, Atomic structure & nomenclature42
Chemical formulas for molecules•Molecular formula: the actual numbers of•Molecular formula: the actual numbers of atoms of each element in the compound
•Empirical formula: the simplest whole number ratio of elements in the compoundp
S. Ensign, Atomic structure & nomenclature43
Some compounds cannot be represented by a “molecular” formula
“Allotropes” of carbon: diamond, graphite, and buckyballp g p y
S. Ensign, Atomic structure & nomenclature44Graphite, Cn diamond, Cn buckyball, C60
Structural formulaA pictorial representation of a molecular formula Shows how the molecular formula. Shows how the atoms are joined together.
S. Ensign, Atomic structure & nomenclature45
Molecular formula: the numbers of atoms of each element in the molecule
NH3
Structural formula: A pictorial representation showing how atoms are connected (arranged) inshowing how atoms are connected (arranged) in the compound
P ti d i A t t l f l idiPerspective drawing: A structural formula providing information about the 3-dimensional shape of the molecule
Ball and stick model: A perspective drawing where bonded atoms are shown as balls and sticksbonded atoms are shown as balls and sticks
Space filling model: A 3-dimensional model showing the relative sizes of individual atoms and
S. Ensign, Atomic structure & nomenclature46
showing the relative sizes of individual atoms and their distances from one another
Subscripts and superscriptsSubscripts and superscripts• For an element, subscripts and superscripts to the
LEFT of the element indicate the atomic numberLEFT of the element indicate the atomic number and mass number of that element P32
15• For a compound subscripts to the RIGHT of the
P15• For a compound, subscripts to the RIGHT of the
elements tell us how many atoms of that element are present in the compound (no subscript = 1)p p ( p )– CH4, C2H4, CO2, H2O, NH3
S. Ensign, Atomic structure & nomenclature47
Ions: atoms that have gained orIons: atoms that have gained or lost electrons and hence have a net
ti iti h Thnegative or positive charge. The nucleus of the atom remains unchanged.
C ti l t ( ) d Xn+• Cations: electron(s) removed Xn+
• Anions: electron(s) added Yn-
S. Ensign, Atomic structure & nomenclature48
Formation of a sodium cation
11 11 p+
Remove one e-
11 p+ 11 p+
11 p+
11 e-
11 p+
10 e-11 e 10 e
Na Na1+ = Na+
S. Ensign, Atomic structure & nomenclature49
Formation of a chloride anion
17
add one e-
1717 p+ 17 p+
17 p+
17 e-17 p+
18 e-17 e
Cl18 e
Cl-
S. Ensign, Atomic structure & nomenclature50
IonsIons
• Metal atoms lose electrons to form cationsMetal atoms lose electrons to form cations• Nonmetal atoms gain electrons to make
anionsanions• WHY??
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Many atoms gain or lose electrons in order to obtain the same number of electrons as a nearby noble gassame number of electrons as a nearby noble gas
Li+ F-N3-
H+ H-
O2-
Na+
K+
Cl-
B
N
P3-
O
S2-
S2
Mg2+
C 2+
Al3+
K+
Rb+
Br-
I-
S2-
Te2-
Ca2+
Sr2+
Cs+ Ba2+
S. Ensign, Atomic structure & nomenclature52
Predict the charges on the ions formed by the following y gelements:
Element nearest noble gas ionNaMgCsRaRaFClONP
S. Ensign, Atomic structure & nomenclature53
PAlC
Complete the following table using the Periodic Table and the information provided
Symbol 85Y 120Sn2+ 127Te
# protons 65
# neutrons 94 32
# electrons 63 27
Atomic # 53
Mass # 127
Charge 0 -1
S. Ensign, Atomic structure & nomenclature54
Binary ionic compoundsy pCombinations of metal cations and nonmetal anions bonded togethernonmetal anions bonded together through strong electrostatic attractive forces (an “ionic bond”)forces (an ionic bond )
Contrast molecular compounds, which areContrast molecular compounds, which are formed from combinations of nonmetals only (H2O, CO2, CH4, etc.) bonded by shared(H2O, CO2, CH4, etc.) bonded by shared electron pairs in a “covalent bond”Combinations of metalloids and nonmetals
S. Ensign, Atomic structure & nomenclature55
S. Ensign, Chem. 121055
Combinations of metalloids and nonmetals are usually classified as “molecular”
Reaction of Na and Cl
Ionic compounds are always represented by empirical formulas: there is no discrete molecular formula for an ionic
S. Ensign, Atomic structure & nomenclature56
formulas: there is no discrete molecular formula for an ionic solid
Writing empirical formulas for ionic compoundsA d i h l 2 l i “bi• A compound with only 2 elements is a “binary compound”F i i d l th b l f th• For ionic compounds, place the symbol for the metal before that of the nonmetal (cation first, anion second)anion second)
• Subscripts after the elements designate the number of atoms of that type in the compoundnumber of atoms of that type in the compound
• When writing the formula of a neutral ionic compound, net charge = 0, so the charges mustcompound, net charge 0, so the charges must balance for each ion
S. Ensign, Atomic structure & nomenclature57
Writing empirical formulas for ionic compounds• A compound with only 2 elements is a “binary• A compound with only 2 elements is a binary
compound”• For ionic compounds, place the symbol for the metal
before that of the nonmetal (cation first, anion second))
• Subscripts after the elements designate the number of atoms of that type in the compound
• When writing the formula of a neutral ionic compound, net charge = 0, so the charges must balance for each ion
S. Ensign, Atomic structure & nomenclature58
Writing empirical formulas for ionic compounds• A compound with only 2 elements is a “binary• A compound with only 2 elements is a binary
compound”• For ionic compounds, place the symbol for the metal
before that of the nonmetal (cation first, anion second))
• Subscripts after the elements designate the number of atoms of that type in the compound
• When writing the formula of a neutral ionic compound, net charge = 0, so the charges must balance for each ion
S. Ensign, Atomic structure & nomenclature59
Polyatomic ions: a compound of two or more nonmetal atoms joined throughmore nonmetal atoms, joined through covalent bonds, that forms a single charged unit (i e a molecular compoundcharged unit (i.e., a molecular compound that does not have a neutral charge)
SO3 is a molecular compoundSO4
2- is a polyatomic anion
NH3 is a molecular compoundNH4
+ is a polyatomic cation4 p y
S. Ensign, Atomic structure & nomenclature60
Common polyatomic ionsCommon polyatomic ionsName Formula Charge
A i i NH + +1Ammonium ion NH4+ +1
Nitrate ion NO3- -1
Chlorate ion ClO3- -1
Carbonate ion CO32- -2Carbonate ion CO3 2
Sulfate ion SO42- -2
Peroxide ion O22- -2
Phosphate ion PO43- -3
S. Ensign, Atomic structure & nomenclature61
Ionic compounds containing polyatomic ionsName Formula Charge
Ammonium ion NH4+ +1XmYn Nitrate ion NO3- -1
Chlorate ion ClO3- -1
Carbonate ion CO 2- 2
XmYn
Carbonate ion CO32- -2
Sulfate ion SO42- -2
Peroxide ion O22- -2Peroxide ion O2 2
Phosphate ion PO43- -3
S. Ensign, Atomic structure & nomenclature62
A fail proof way to write the correct formula for an ionic compoundfor an ionic compound
Xn+ Ym-Xn Ymnm
X YXmYn
R d t i i l f l if b di idi b th
S. Ensign, Atomic structure & nomenclature63
Reduce to an empirical formula, if necessary, by dividing by the appropriate integer (e.g. Mg2O2 MgO)
A fail proof way to deduce the ion charges on ions present in an ionic compound
X Yon ions present in an ionic compound
n+ m-XmYn
Xn+ Ym-
Be sure the magnitude of the ion charge matches what it should
S. Ensign, Atomic structure & nomenclature64
g gbe based on position in the periodic table for a monatomic ion, or the known charge for a polyatomic ion
Write empirical formulas for the bi i i d f d f binary ionic compounds formed from the combinations of Co2+, Mg2+, and Li+ with S2-, PO4
3-, and SO42-
S. Ensign, Atomic structure & nomenclature65
Classify the following compounds as ionic or molecular. Which molecular formulas are also empirical formulas?p
compound Type? Empirical?NF33
C6H14
K2SP SP4S3
MgOKBrOF2
AsH3
XeF2
NaFPbF2
S. Ensign, Atomic structure & nomenclature66
2
P2F4
Nomenclature: The naming of substancesB bl tBe able to name:•Constituent atoms in molecular compoundsC tit t i i i i d•Constituent ions in ionic compounds
•Ionic compoundsM l l d
I i d d i diff t
•Molecular compounds•AcidsIonic compounds are named using a different set of rules than covalent compounds
S. Ensign, Atomic structure & nomenclature67
Naming ionic compoundsNaming ionic compounds
• Cation name followed by anion nameCation name followed by anion name• So, how do we name cations and anions?
S. Ensign, Atomic structure & nomenclature68
Naming monatomic cations (+ ions)• Cations for which only one charge can be formed
(group 1A, 2A, 3A, some “d” block): the name is simply the name of the metal followed by “ion”simply the name of the metal followed by “ion”
• Cations of transition (“d block”) metals that can form more than one charge:form more than one charge:– “New” method: Place the charge in parentheses after the
metal name and before “ion”– “old” method for metals that form two charges: use root
of latin name + “ous” for lower charge, or “ic” for higher h f ll d b “i ”charge, followed by “ion”
S. Ensign, Atomic structure & nomenclature69
Naming monatomic cations (+ ions)Cations for which only one charge can be formed
(group 1A 2A 3A some “d” block): the name(group 1A, 2A, 3A, some d block): the name is simply the name of the metal followed by “ion”
S. Ensign, Atomic structure & nomenclature70
Naming monatomic cations (+ ions)Cations of transition metals that can form more
than one charge:than one charge:“New” method: Place the charge in
parentheses after the metal name and before “ion”
“old” method for metals that form twoold method for metals that form two charges: use root of latin name + “ous” for lower charge, or “ic” for higher charge, followed by “ion”
S. Ensign, Atomic structure & nomenclature71
There aren’t many polyatomic cations to worry aboutCommon polyatomic ionsCommon polyatomic ionsName Formula Charge
A i i NH + +1Ammonium ion NH4+ +1
Nitrate ion NO3- -1
Chlorate ion ClO3- -1
Carbonate ion CO32- -2Carbonate ion CO3 2
Sulfate ion SO42- -2
Peroxide ion O22- -2
Phosphate ion PO43- -3
S. Ensign, Atomic structure & nomenclature72
Naming monatomic anions (- ions)• Drop the ending of the name of the elementDrop the ending of the name of the element
and add “ide” + “ion”H-HN3-
O2-O2
F-
S2S2-
Br-
S. Ensign, Atomic structure & nomenclature73
There are a lot more polyatomic anions to worry about
S. Ensign, Atomic structure & nomenclature74
Making sense of polyatomic anion namesMaking sense of polyatomic anion names
• Some of them also end in “ide”Some of them also end in ide– Hydroxide (know this one now)
Cyanide– Cyanide– Peroxide
azide– azide
S. Ensign, Atomic structure & nomenclature75
Making sense of polyatomic anion namesXO m• Oxyanions are very common
– Elements that form only 2 oxyanions:XOn
m-
• Charges on both ions are generally the same• One with less oxygens = “ite”
O ith “ t ”• One with more oxygens = “ate”– Elements that form 3 or 4 oxyanions:
Ch b th i ll th• Charges on both ions are generally the same• hypo = less• per = moreper = more
– Hydrogen ions (H+) can combine with oxyanions to form “new” hydrogen oxyanions
S. Ensign, Atomic structure & nomenclature76
oxyanions to form new hydrogen oxyanions
Making sense of polyatomic anion namesXO m
• Note I am going to give you the formulas XOn
m-
g g g yand names for the following oxyanions on the exam information sheet. At some point pyou will need to memorize these though.
Formulas and names of common polyatomic ions:
Carbonate ion = CO32- Sulfate ion = SO4
2-3 4
Nitrate ion = NO3- Perchlorate ion = ClO4
-
Ph h t i PO 3
S. Ensign, Atomic structure & nomenclature77
Phosphate ion = PO43-
Making sense of polyatomic anion namesXOXOn
m-• Elements that form only 2 oxyanions:
• Charges on both ions are generally the same• Charges on both ions are generally the same• One with less oxygens = “ite”• One with more oxygens = “ate”
Formulas and names of common polyatomic ions:Carbonate ion = CO3
2- Sulfate ion = SO42-
Nitrate ion = NO3- Perchlorate ion = ClO4
-
Phosphate ion = PO43-yg
• Nitrogen combines with O to form two common oxyanions that have one N: NO2
- and NO3-oxyanions that have one N: NO2 and NO3
• Since we know from the table that NO3- is the
nitrate ion, we can predict that NO2- is the nitrite ionnitrate ion, we can predict that NO2 is the nitrite ion
• Note the ion charges on NO2- and NO3
- are the same (-1 in each case)
S. Ensign, Atomic structure & nomenclature78
( )
Making sense of polyatomic anion namesXOXOn
m-• Elements that form only 2 oxyanions:
• Charges on both ions are generally the same• Charges on both ions are generally the same• One with less oxygens = “ite”• One with more oxygens = “ate”
Formulas and names of common polyatomic ions:Carbonate ion = CO3
2- Sulfate ion = SO42-
Nitrate ion = NO3- Perchlorate ion = ClO4
-
Phosphate ion = PO43-yg
• Sulfur combines with O to form two common oxyanions that have one S: SO3
2- and SO42-oxyanions that have one S: SO3 and SO4
• Since we know from the table that SO42- is the
sulfate ion, we can predict that SO32- is the sulfitesulfate ion, we can predict that SO3 is the sulfite
ion• Note the ion charges on SO3
2- and SO42- are the
S. Ensign, Atomic structure & nomenclature79
g 3 4same (-2 in each case)
Making sense of polyatomic anion namesXO• Elements that form only 2 oxyanions:
• Charges on both ions are generally the same
XOnm-
• Charges on both ions are generally the same• One with less oxygens = “ite”• One with more oxygens = “ate”
Formulas and names of common polyatomic ions:Carbonate ion = CO3
2- Sulfate ion = SO42-
Nitrate ion = NO3- Perchlorate ion = ClO4
-
Phosphate ion = PO43-yg
• Phosphorus combines with O to form two common oxyanions: PO3
3- and PO43-common oxyanions: PO3 and PO4
• Since we know from the table that PO43- is the
phosphate ion, we can predict that PO33- is thephosphate ion, we can predict that PO3 is the
phosphite ion• Note the ion charges on PO3
3- and PO43- are the g 3 4
same (-3 in each case)S. Ensign, Atomic structure & nomenclature
80
Making sense of polyatomic anion namesXOXOn
m-
• Carbon combines with O to form only common oxyanion with one C: CO3
2-
• CO32- is the carbonate ion, and there is no such
thing as the carbonite ionFormulas and names of common polyatomic ions:Carbonate ion = CO3
2- Sulfate ion = SO42-
Nitrate ion = NO3- Perchlorate ion = ClO4
-
Phosphate ion = PO43-
S. Ensign, Atomic structure & nomenclature81
Making sense of polyatomic anion names• Elements that form 4 oxyanions: XOn
- , where “X” is a halogen (Cl, Br, I) and n = 1-4 Formulas and names of common polyatomic ions:
Carbonate ion = CO32- Sulfate ion = SO4
2-
Nitrate ion = NO3- Perchlorate ion = ClO4
-
Phosphate ion = PO43-
• Charges on all 4 ions are the same (-1)• Take the root of the halogen (chlor, bromo, g ( , ,
iodo)• Hypo___ ite = XO- (e.g. hypochlorite)• ___ ite = XO2
- (e.g. chlorite)• ate = XO2
- (e.g. chlorate)
S. Ensign, Atomic structure & nomenclature82
___ 2 ( g )• Per ___ ate = XO4
- (e.g. perchlorate)
Oxyanions can also be formed with the formulas X O p- and have names that areformulas XnOm
p and have names that are not easy to predict. You do not need to memorize or be familiar with any of thesememorize or be familiar with any of these for chemistry 1210
• S2O32- is the thiosulfate ion
S O 2 i th dithi t i• S2O42- is the dithionate ion
• S4O62- is the tetrathionate ion
S. Ensign, Atomic structure & nomenclature83
There are a few oxyanions consisting of metals combined with oxygens bondedmetals combined with oxygens, bonded similarly to the bonds between nonmetals and oxygens in oxyanions You don’t needand oxygens in oxyanions. You don t need to memorize the names of these now, but h lhere are a couple common ones.
• MnO4- = permanganate ion (used widely in gen
chem labs)• Cr2O7
2- = dichromate ion (also used widely in gen chem labs)
S. Ensign, Atomic structure & nomenclature84
Oxyanion examples– Elements that form only 2 oxyanions:
XOnm-
• Charges on both ions are generally the same• One with less oxygens = “ite”• One with more oxygens = “ate”
– Elements that form 3 or 4 oxyanions:Elements that form 3 or 4 oxyanions:• Charges still the same• hypo = less• per = more
H d i (H+) bi ith i t– Hydrogen ions (H+) can combine with oxyanions to form “new” hydrogen oxyanions
S. Ensign, Atomic structure & nomenclature85
Information I will give you on examInformation I will give you on examFormulas and names of common polyatomic ions:
C b t i CO 2-Carbonate ion = CO32
Nitrate ion = NO3-
Phosphate ion = PO43-
2Sulfate ion = SO42-
Perchlorate ion = ClO4-
Ammonium ion = NH4+Ammonium ion NH4
You must know the hydroxide ion (OH-)You must know the hydroxide ion (OH )
S. Ensign, Atomic structure & nomenclature86
Naming ionic compounds:C ti f ll d b i•Cation name followed by anion name
•Examples: Name the following ionic compounds:Formulas and names of common polyatomic ions:
2
•CaBr2
•Mg(OH)2
Carbonate ion = CO32-
Nitrate ion = NO3-
Phosphate ion = PO43-
Sulfate ion = SO42-
Perchlorate ion = ClO4-
Ammonium ion = NH +Mg(OH)2
•Co2O3
Ammonium ion = NH4
•TiCl2
•(NH4)2CO3( 4)2 3
•Na2SO4Wherever possible, predict charges on simple cations and anions based on
S. Ensign, Atomic structure & nomenclature87
•NaHSO4and anions based on positions in periodic table
Acids• A simple working definition (for now): a
compound that dissolves in water to produce p phydrogen ions and a corresponding anion
HnX
S. Ensign, Atomic structure & nomenclature88
Naming acids HnX• Binary acids:
– Begin with “hydro”
n
eg yd o– Follow “hydro” with anion name, replacing “ide”
with “ic”– Complete the naming with “acid”
S. Ensign, Atomic structure & nomenclature89
Adding hydrogens to oxyanions to form neutral acids:
mH+ + XOnm- HmXOn
• Change “___ite ion” to “___ous acid• Change “ ate ion” to ous acidChange ___ate ion to ___ous acid• Retain “hypo” or “per” if they are present
S. Ensign, Atomic structure & nomenclature90
Oxyanion ion Formula Oxyacid Formula
Nitrite ion NO2- Nitrous acid HNO2
Nitrate ion NO3- Nitric acid HNO3
Hypochlorite ion ClO3- Hypochlorous acid HClO
chlorite ion ClO2- Chlorous acid HClO2
chlorate ion ClO3- Chloric acid HClO3
Perchlorate ion ClO4- Perchloric acid HClO4
Carbonate ion CO32- Carbonic acid H2CO3Carbonate ion CO3 Carbonic acid H2CO3
Sulfate ion SO32- Sulfurous acid H2SO3
Sulfate ion SO42- Sulfuric acid H2SO4
Phosphite ion PO33- Phosphorous acid H3PO3
Phosphate ion PO43- Phosphoric acid H3PO4
S. Ensign, Atomic structure & nomenclature91
Naming molecular compoundsNaming molecular compounds
• Nonmetal + nonmetalNonmetal + nonmetal• Many are “binary”
S. Ensign, Atomic structure & nomenclature92
Naming binary molecular compounds:In general the element closer to the metals is listed first•In general, the element closer to the metals is listed first
•the first element in the formula is named first, using it’s normal elemental name
•For the second element in the formula , drop the ending of the element name and replace with “ide”
•Use prefixes to indicate the number(s) of atom(s) in theUse prefixes to indicate the number(s) of atom(s) in the binary compounds (don’t use “mono” for 1st element)
-Mono-Di-Tri-Tetra
S. Ensign, Atomic structure & nomenclature93
-penta
Prefixes used when naming binary molecular compoundsPrefix Meaningmono 1di 2di 2tri 3tetra 4tetra 4penta 5hexa 6hepta 7nona 8deca 9
S. Ensign, Atomic structure & nomenclature94
Naming binary molecular compounds:•In general, the element closer to the metals is listed first
•the first element in the formula is named first, using it’s normal elemental name
•For the second element in the formula , drop the ending of the element name and replace with “ide”
•Use prefixes to indicate the number(s) of atom(s) in the binary compounds (don’t useatom(s) in the binary compounds (don t use “mono” for 1st element)
S. Ensign, Atomic structure & nomenclature95
Name these molecular and ionic compoundscompound Type? Empirical? NameNF3
C6H14C6H14
K2SP4S3
MgOKBrOFOF2
AsH3
XeF2
NaFPbF2
P F
S. Ensign, Atomic structure & nomenclature96
P2F4
Give formulas for each of the following ionic compoundsmp
a) Ammonium nitrateb) Cobalt (II) nitrateb) Cobalt (II) nitratec) Nickel (II) sulfated) Ni k l (III) idd) Nickel (III) cyanidee) Vanadium (III) oxidef) Ammonium sulfate
Formulas and names of common polyatomic ions:
Carbonate ion = CO32-
Nitrate ion = NO3-
Phosphate ion = PO43-
S. Ensign, Atomic structure & nomenclature97
Phosphate ion = PO4 Sulfate ion = SO4
2- Perchlorate ion = ClO4
- Ammonium ion = NH4
+
Name the following compounds:
a) MgBr2
b) Li COb) Li2CO3
c) KHSO3
d) KMnO4
e) (NH4)2Se) (NH4)2Sf) CuClg) CuClg) CuCl2
S. Ensign, Atomic structure & nomenclature98
Give formulas for:
a) Carbon dioxideb) Phosphor s triiodideb) Phosphorus triiodidec) Sulfur dichlorided) Xenon trioxidee) Dioxygen difluoridee) Dioxygen difluoride
S. Ensign, Atomic structure & nomenclature99
Name the following molecular compounds:
a) N2F4
b) HBrb) HBrc) SF4
d) ClF3
e) BCl3e) BCl3f) P4O10
S. Ensign, Atomic structure & nomenclature100