Download Ch. 9

Ch. 9
“Little Johnny took a drink,
Now he shall drink no more.
For what he thought was H2O,
Was H2SO4.”
Chemical Names and Formulas
"H-O-H"?! WHAT'S
THAT SPELL?!
mis
Website: Dihydrogen monoxide Information Campaign
WATER?
Naming Ions
• *Element Name Search Activity* pg. 252
• Monatomic ions = ions consisting of a single
atom w/a pos. or neg. charge resulting from
the loss or gain of 1 or more valence electrons
• Polyatomic ions = ions composed of more
than 1 atom
Vocabulary
CHEMICAL FORMULA
IONIC
COVALENT
formula
unit
molecular
formula
NaCl
CO2
Vocabulary
COMPOUND
2 elements
binary
compound
NaCl
more than 2
elements
ternary
compound
NaNO3
Vocabulary
ION
1 atom
2 or more atoms
monatomic
Ion
polyatomic
Ion
+
Na
NO3
-
Cations
•
•
•
•
•
Metals
Under aged Pb walks into a bar and
the bartender turns to the gold
Lose electrons
Bouncer and says, “Au, get the lead
Pos. charge
out!”
Groups 1A-3A sometimes 4A
When the metals in Groups 1A, 2A, & 3A lose
electrons, they form cations w/ pos. charges equal to
their group #
• The names of the cations are the same as the name of
the metal followed by the word ion or cation
– EX: Al3+ is the aluminum ion
Anions
•
•
•
•
Nonmetals
Gain electrons
Negative charge
The charge of any ion of a Group A nonmetal is
determined by subtracting 8 from the group
number
– 7A (7 – 8 = -1), 6A = -2, 5A = -3
• Anion names start w/ the stem of the element
name and end in –ide
– F-(fluoride), Cl-(chloride), O2-(oxide), S2-(sulfide), N3(nitride), P3-(phosphide), As3- (arsenide)
Transition Metal Ions
• Pos. charged cations w/ charges of +1, +2, or
+3
• Groups 1B-8B
• Some may form more than 1 cation w/diff.
charges
• Roman numeral after the metal name
describes the charge OR –ous for the smaller
and –ic for the larger charge
• *C.P. 9.1, P.P. 1-2 pg. 256
Polyatomic Ions
• Most names end in –ite or –ate but
some end in –ium or –ide
• Some begin with a H so we say
Hydrogen Phosphate for HPO4. The biprefix means: add H+ ions to the anion
until its charge is -1, So H2PO4 is
biphosphate and HCO3 is bicarbonate.
• *9.1 sect. assessment pg. 258
Nomenclature - Humor
Fe2+
Fe2+
Fe2+
Fe2+
Fe2+
Fe2+
Fe2+
Fe2+
“Ferrous Wheel”
Fe = iron (Latin = ferrum)
Fe2+ = lower oxidation state = ferrous
Fe3+ = higher oxidation state = ferric
BaNa2
“BaNaNa”
What weapon can you make
from the elements nickel,
potassium and iron?
A KNiFe
Naming Ionic Compounds
• Binary compounds – two types of elements
• Ternary compounds – more than two types of
elements
• Cations go 1st – cation can be metal or polyatomic ion
– For metals that have only 1 possible charge (valency,
oxidation #), the name of the metal is used
• Examples are Group 1 metals (1+), Group II metals (2+), Al+3, Zn+2,
Ag+1
– For metals that can have more than one charge, the name
of the metal is succeeded by the valency in capital Roman
numerals in () parentheses OR by using the suffix –ous for
the lowest valency & -ic for the highest valency
Cont…
• Anions go 2nd – neg. charged element or
polyatomic ion
– Neg. charged elements have the suffix –ide
• Ex: oxide O, sulfide, fluoride, nitride
– Polyatomic ions which include oxygen in the anion
have the suffixes –ate or –ite. “ate” means there is
more oxygen in the anion than one ending in “ite”
• Ex: sulfate SO42- and sulfite SO32-, nitrate NO3- and nitrite
NO2• Exception: OH- hydroxide
• *Practice: Fe(OH)3, KNO3, NH4Br, Ca(OH)2, CuSO4,
Cu2O, Al2S3
Bellringer 1 (Name the following)
•
•
•
•
•
1) CaCl2
2) PO4-3
3) CO3-2
4) AgBr
5) Al2O3
Polyatomic Ion:
a group of atoms that stay together and have a single, overall charge.
BrO41-
Perbromate ion
CO42ClO41IO41NO41-
PO53SO521 more oxygen
BrO31-
BrO1-
Bromate ion
BrO21-
Bromite ion
CO32-
CO22-
CO2-
ClO31-
ClO21-
ClO1-
IO31-
IO21-
IO1-
NO31-
NO21-
NO1-
PO43-
PO33-
PO23-
SO42-
SO32-
SO22-
“normal”
1 less oxygen
Carbonate ion
Chlorate ion
Iodate ion
Nitrate ion
Phosphate ion
Sulfate ion
Hypobromite ion
2 less oxygen
1+
H
Binary
Compounds
2
3
4
Binary compounds that contain a metal 5
of fixed oxidation number
(group 1, group 2, Al, Zn, Ag, etc.), and 6
7
a non-metal.
He
2+
3+
Be
B
C
N
O
F
2
Ne
3
4
Na Mg
5
Al
6
Si
7
P
8
S
9
Cl
10
Ar
1
1
Li
1+ 2+
11 12
K Ca Sc
Ti
13 14 15 16
Cu Zn Ga Ge As Se
17
Br
18
Kr
19 20
Rb Sr
21
Y
22 23 24 25 26 27 28 29 30 31 32 33 34
Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te
35
I
36
Xe
37 38
Cs Ba
39
40
Hf
55 56
Fr Ra
87
88
*
W
V
41
Ta
Cr Mn Fe Co
42 43 44 45
W Re Os Ir
72 73 74 75 76 77
Rf Db Sg Bh Hs Mt
Ni
46 47 48 49 50
Pt Au Hg Tl Pb
51 52 53 54
Bi Po At Rn
78
83
79
80
81
82
104 105 106 107 108 109
To name these compounds, give the name of metal followed by the
name of the non-metal, with the ending replaced by the suffix –ide.
Examples:
NaCl
sodium chlor ide
(Na1+ Cl1-)
CaS
calcium sulf ide
(Ca2+
AlI3
aluminum iodide
(Al3+ 3 I1-)
S2-)
84
85
86
Practice
•
•
•
•
•
•
BaO
NaBr
MgI2
KCl
SrF2
CsF
Writing Formulas of Ionic Compounds
chemical formula:
has neutral charge;
shows types of atoms and how many of each
To write an ionic compound’s formula, we need:
1. the two types of ions
2. the charge on each ion
Na1+
and
F1–
NaF
sodium fluoride
Ba2+
and
O2–
BaO
barium oxide
Na1+
and
O2–
Na2O
sodium oxide
Ba2+
and
F1–
BaF2
barium fluoride
Criss-Cross Rule
Example: Aluminum Chloride
Step 1:
write out name with space
Step 2:
Al
3+
Cl
1-
write symbols & charge of elements
Step 3:
Al 1
Cl 3
criss-cross charges as subsrcipts
Step 4:
combine as formula unit
(“1” is never shown)
*ALWAYS REMEMBER TO
SIMPLIFY WHEN FINISHED
AlCl3
Rules for Parentheses
Parentheses are used only when the following
two condition are met:
1. There is a radical (polyatomic ion) present and…
2. There are two or more of that radical in the formula.
Examples:
NaNO3
NO31- is a radical, but there is only one of it.
Co(NO3)2
NO31- is a radical and there are two of them
(NH4)2SO4
NH41+ is a radical and there are two of them;
SO42- is a radical but there is only one of it.
Co(OH)2
OH1- is a radical and there are two of it.
Al2(CO3)3
CO32- is a radical and there are three of them.
NaOH
OH1- is a radical but there is only one of it.
Writing Formulas w/Polyatomic Ions
Parentheses are required only when you need more
than one “bunch” of a particular polyatomic ion.
Ba2+
and
SO42–
BaSO4
barium sulfate
Mg2+
and
NO21–
Mg(NO2)2
magnesium nitrite
NH41+
and
ClO31–
NH4ClO3
ammonium chlorate
Sn4+
and
SO42–
Sn(SO4)2
tin (IV) sulfate
Fe3+
and
Cr2O72–
Fe2(Cr2O7)3
iron (III) dichromate
NH41+
and
N3–
(NH4)3N
ammonium nitride
Hydrates
• Hydrates = ionic compounds that absorb H2O
into their solid structures
– Ex: CuSO4 . 5H2O copper (II) sulfate pentahydrate
– MgSO4 . 7H2O magnesium sulfate heptahydrate
•
•
•
•
C.P. 9.2, P.P. 10-11 pg. 263
C.P. 9.3, P.P. 12-13 pg. 265
9.2 Sect. Assessment 14-19 pg. 266
*Making & Naming an Ionic Compound Demo
pg. 262
Molecular Compound
A compound containing atoms of two or more elements that are bonded together by sharing electrons.
Silicon dioxide, SiO2, is a molecular compound. It is also a mineral called quartz (left).
Quartz is found in nearly every type of rock. Most sand grains (center) are bits of quartz.
Glass is made from sand.
Naming Molecular Compounds
• The more electronegative element is written last and w/ ide
• Use prefixes to tell you the subscript in each
• Mono is not written w/ the 1st word of a compound’s name
(Ex: CO2)
• Prefixes are sometimes shortened to make a name easier
to say (Ex: CO is carbon monoxide not mono oxide)
• Sometimes use common names instead of formal names
(Ex: O2 is oxygen not dioxygen, NH3 is ammonia, and H2O is
water not dihydrogen monoxide)
• *Practice: N2O4, PCl5, NO2, BF3, NF3, P2O5, N2O5, SO2, SiO2,
PCl3
• *9.3 Sect. Assessment 20-25 pg. 270
Bellringer 2 (Write or name the
following)
•
•
•
•
•
1) N2O
2) lead (IV) oxide
3) SiO3
4) XeF4
5) ammonium nitride
Writing Formulas of Covalent Molecules
 Covalent Molecules
contain two types of nonmetals
Key: FORGET CHARGES
What to do:
Use Greek prefixes to indicate how many atoms
of each element, but don’t use “mono” on first element.
1 – mono
2 – di
3 – tri
4 – tetra
5 – penta
6 – hexa
7 – hepta
8 – octa
9 – nona
10 – deca
Writing Formulas of Covalent Molecules
EXAMPLES:
carbon dioxide
CO
dinitrogen trioxide
N2O5
carbon tetrachloride
NI3
CO2
carbon monoxide
N2O3
dinitrogen pentoxide
CCl4
nitrogen triiodide
Practice Writing and Naming
Compounds
•
(NH4)2S2O3
• FeO
•
AgBrO3
•
•
(NH4)3N
Fe2O3
•
U(CrO4)3
•
CuBr
•
Cr2(SO3)3
•
iron (III) nitrate
•
ammonium phosphide
•
ammonium chlorite
•
zinc phosphate
•
lead (II) permanganate
• CuBr2
• cobalt (III) chloride
• tin (IV) oxide
• tin (II) oxide
Exceptions!
Two exceptions to the simple –ide ending are the diatomic oxide ions,
O22- and O21-.
O22- is called peroxide
Note the differences.
O21- is called superoxide.
barium oxide
barium peroxide
BaO
__________
BaO2
__________
sodium oxide
sodium peroxide
Na2O
__________
Na2O2
__________
potassium oxide
potassium superoxide
K2O
__________
KO2
__________
Ba2+
Na1+
Do Not Reduce to lowest terms!
K1+
Acids
• Acid = a compound that contains one or more
hydrogen atoms and produces hydrogen ions
(H+) when dissolved in water.
• Consist of an anion combined w/as many
hydrogen ions needed to become electrically
neutral in the form (HnX)
3 Rules to Naming Acids:
• 1. When the name of the anion (X) ends in –ide, the acid
name begins w/the prefix hydro-. The stem of the anion
has the suffix –ic and is followed by the word acid
– HCl = hydrochloric acid
• 2. When the anion name ends in –ite, the acid name is the
stem of the anion w/the suffix –ous, followed by the word
acid
– H2SO3 = sulfurous acid
• 3. When the anion name ends in –ate, the acid name is
the stem of the anion w/the suffix –ic followed by the
word acid
– HNO3 = nitric acid
Naming Bases
• Base = ionic compound that produces
hydroxide ions when dissolved in water
• Bases are named in the same way as other
ionic compounds – the name of the cation is
followed by the name of the anion
– EX: NaOH = sodium hydroxide
– Al(OH)3 = aluminum hydroxide
• *9.4 Sect. Assessment 26-33 pg. 273
Formula  Name?
Metal + Nonmetal?
(Except: NH4+)
Two Nonmetals?
Ionic
d,f-block
Pb,Sn
Multiple
Columns 1, 2, 13
Ag+, Zn2+
Single
Covalent
Steps 1 & 4 ONLY
1. Write name of cation (metal)
2. Determine the charge on the metal by balancing the
(-) charge from the anion
3. Write the charge of the metal in Roman Numerals
and put in parentheses
4. Write name of anion
(Individual anions need –ide ending!)
Use Prefixes!!!
*Mono*
Di
Tri
Tetra
Penta
Hexa
Hepta
Octa
Nona
Deca
Name  Formula?
No Prefixes?
Ionic
Prefixes?
Covalent
1. Determine the ions present
and the charge on each
(Roman Numeral = cation
charge, otherwise use PT)
1. FORGET CHARGES!!!
2. Balance formula (criss-cross)
3. Do NOT reduce subscripts!
3. Reduce subscripts (if needed)
2. Use prefixes to determine
subscripts