chapters 8 & 9
DESCRIPTION
Chapters 8 & 9. Naming Compounds Writing Formulas. Compounds. Follow the Law of Definite Proportion. Have a constant composition. Have to add the same number of atoms every time. Two types. Two Types of Compounds. 1 Ionic Compounds Made of cations and anions. Metals and nonmetals. - PowerPoint PPT PresentationTRANSCRIPT
Chapters 8 & 9Naming Compounds
Writing Formulas
Compounds Follow the Law of Definite Proportion. Have a constant composition. Have to add the same number of atoms
every time. Two types.
Two Types of Compounds1 Ionic Compounds Made of cations and anions. Metals and nonmetals. The electrons lost by the cation are
gained by the anion. The cation and anions surround each
other. Smallest piece is a FORMULA UNIT.
Crystalline Structure – Ionic Compound
Two Types of Compounds2 Molecular Compounds
Made of molecules. Made by joining nonmetal atoms
together into molecules. H2O, CO2, C6H12O6
Chemical Formulas Shows the kind and number of
atoms in the smallest piece of a substance.
Molecular formula- number and kinds of atoms in a molecule.
CO2
C6H12O6
Two Types of Compounds
Smallest Piece
Melting Point
State
Types of Elements
Formula Unit Molecule
Metal and Nonmetal
Nonmetals
SolidSolid, Liquid or Gas
High >300ºC Low <300ºC
Ionic Molecular
Chemical Formulas More than one atom? –use a
subscript (H2O) There are 7 diatomic elements Hydrogen (H2), Nitrogen (N2),
Oxygen (O2), Fluorine (F2), Chlorine (Cl2), Bromine (Br2), and Iodine (I2)
Remember: “Br I N Cl H O F”
+2
+1
+3 -3 -2 -1
Systematic Naming There are too many compounds to
remember the names of them all. Compound is made of two or more
elements. Put together atoms. Name should tell us how many and
what type of atoms.
Naming Ions We will use the systematic way. Cation- if the charge (oxidation #) is
always the same, use name of the metal.
Transition metals can have more than one charge or oxidation number.
Therefore, indicate the charge with roman numerals in parenthesis.
Fe+3 is named - iron (III) ion Movie
Exceptions: Some of the transition metals have
only one ionic charge:
–Do not use roman numerals for these:
–Silver is always 1+ (Ag1+)
–Cadmium and Zinc are always 2+ (Cd2+ and Zn2+)
Metals with Multiple ChargesTransition MetalsTransition Metals
Here it is easier to list the ones that only have a single common oxidation state.
All Group 3B - 3+
Ni, Zn, Cd - 2+
Ag - 1+
Lanthanides and actinides - 3+
Name These Ions
Na+1 Ca+2 Al+3 Fe+3 Fe+2 Pb+2 Li+1
sodium ion
calcium ion
aluminum ion
iron (III) ion
iron (II) ion
lead (II) ion
lithium ion
Write Formulas for These Potassium ion Magnesium ion Copper (II) ion Chromium (VI) ion Barium ion Mercury (II) ion
K+1
Mg+2
Cu+2
Cr+6
Ba+2
Hg+2
Naming Anions Anions are always the same. Change the element ending to – ide F-1 Fluorine
Naming Anions Anions are always the same. Change the element ending to – ide F-1 Fluorin
Naming Anions Anions are always the same Change the element ending to – ide F-1 Fluori
Naming Anions Anions are always the same Change the element ending to – ide F-1 Fluor
Naming Anions Anions are always the same Change the element ending to – ide F-1 Fluori
Naming Anions Anions are always the same Change the element ending to – ide F-1 Fluorid
Naming Anions Anions are always the same Change the element ending to – ide F-1 Fluoride
Name These Ions
Cl-1 N-3 Br-1 O-2
Ga+3
Chloride
Nitride
Bromide
Oxide
Gallium (III)
Write These
sulfide ion iodide ion phosphide ion strontium ion
S-2
I-1
P-3
Sr+2
Polyatomic Ions Groups of atoms that stay together and
have a charge. Use your reference sheet Acetate C2H3O2
-1
Nitrate NO3-1
Nitrite NO2-1
Hydroxide OH-1
Permanganate MnO4-1
Cyanide CN-1
Polyatomic Groups with a Charge
Polyatomic Ions Sulfate SO4
-2
Sulfite SO3-2
Carbonate CO3-2
Chromate CrO4-2
Dichromate Cr2O7-2
Phosphate PO4-3
Phosphite PO3-3
Ammonium NH4+1
Common Polyatomic Ions
Ionic Compounds
We’ve named the ions, so now it is time to name the
compounds!
Naming Binary Ionic Compounds Binary Compounds - 2 elements. Ionic - a cation and an anion. To write the names just name the two
ions. Easy with Representative elements. NaCl = Na+ Cl- = sodium chloride
MgBr2 = Mg+2 Br- = magnesium bromide
Naming Binary Ionic Compounds The problem comes with the transition
metals. Need to figure out their charges. The compound must be neutral. Same number of + and – charges. Use the anion to determine the charge
on the positive ion.
Balancing Charges
3P2ZnHow many zinc +2 charges are needed to balance phosphide’s -3 charge?
What subscripts must be placed on the line?
The numbers used must always be whole numbers.
23PZn
Naming Ionic CompoundsMany metals form more than one compound with
some anions.
For these, roman numerals are used in the name to indicate the charge on the metal.
Cu1+ + O2- = Cu2O
copper(I) oxide copper(I) oxide
Cu2+ + O2- = CuO
copper(II) oxide copper(II) oxide
More ExamplesFeCl2 iron(II) chloride
FeCl3 iron(III) chloride
SnS tin(II) sulfide
SnS2 tin(IV) sulfide
AgCl silver chlorideCdS cadmium sulfideNoteNote
Some transition metals only have a single state so the roman numeral may be omitted.
Some main group metals, with high atomic numberhave more than one state, roman numbers are used.
Naming Binary Ionic Compounds Write the name of CuO Need the charge of Cu O is -2 Copper must be +2 Copper (II) oxide Name CoCl3
Cl is -1 and there are three of them = -3 Co must be +3 Cobalt (III) chloride
Naming Binary Ionic Compounds Write the name of Cu2S. Since S is -2, the Cu2 must be +2, so
each one is +1. copper (I) sulfide Fe2O3 Each O is -2 3 x -2 = -6 2 Fe must = +6, so each is +3. iron (III) oxide
Naming Binary Ionic Compounds Write the names of the following KCl Na3N
CrN
Sc3P2
PbO
PbO2
Na2Se
Potassium Chloride
Sodium Nitride
Chromium (III) Nitride
Scandium (II) Phosphide
Lead (II) Oxide
Lead (IV) Oxide
Sodium Selenide
Ternary Ionic Compounds Will have polyatomic ions At least three elements Name the ions
NaNO3
CaSO4
CuSO3
(NH4)2O
Sodium Nitrate
Calcium Sulfate
Copper (II) Sulfite
Ammonium Oxide
Ternary Ionic Compounds
LiCN Fe(OH)3
(NH4)2CO3
NiPO4
Lithium Cyanide
Iron (III) Hydroxide
Ammonium Carbonate
Nickel (III) Phosphate
Writing Formulas The charges have to add up to zero. Get charges on pieces. Cations from name of table. Anions from table or polyatomic. Balance the charges by adding
subscripts. Put polyatomics in parenthesis.
Writing Formulas Write the formula for calcium chloride. Calcium is Ca+2 Chloride is Cl-1 Ca+2 Cl-1 would have a +1 charge. Need another Cl-1 Ca+2 Cl2
-1
Write the Formulas for These lithium sulfide tin (II) oxide tin (IV) oxide magnesium fluoride copper (II) sulfate iron (III) phosphide gallium (I) nitrate iron (III) sulfide
Li2S
SnO
SnO2
MgF2
CuSO4
FeP
GaNO3
Fe2S3
Write the Formulas for These ammonium chloride ammonium sulfide barium nitrate
NH4Cl
(NH4)2S
Ba(NO3)2
Things To Look For If cations have (roman #), the number is
their charge. If anions end in -ide they are probably
off the periodic table (Monoatomic) If anion ends in -ate or -ite it is
polyatomic
Molecular Compounds
Writing Names and Formulas
Molecular Compounds made of just nonmetals smallest piece is a molecule can’t be held together because of
opposite charges can’t use charges to figure out how
many of each atom
Easier Ionic compounds use charges to
determine how many of each.
– Have to figure out charges.
– Have to figure out numbers. Molecular compounds name tells you
the number of atoms. Uses prefixes to tell you the number
Prefixes 1 mono- 2 di- 3 tri- 4 tetra- 5 penta- 6 hexa- 7 hepta- 8 octa-
Prefixes 9 nona- 10 deca- To write the name write two words
Prefixes 9 nona- 10 deca-
To write the name, write two words with
Prefix name Prefix name -ide
Prefixes 9 nona- 10 deca- To write the name write two words
One exception is we don’t write mono- if there is only one of the first element.
Prefix name Prefix name -ide
Prefixes 9 nona- 10 deca- To write the name write two words One exception is we don’t write mono- if
there is only one of the first element. No double vowels when writing names
(oa oo)
Prefix name Prefix name -ide
Name These
N2O
NO2
Cl2O7
CBr4
CO2
BaCl2
Dinitrogen Monoxide
Nitrogen Dioxide
Dichlorine Heptoxide
Carbon Tetrabromide
Carbon Dioxide
Barium Chloride
Write Formulas for These diphosphorus pentoxide tetraiodine nonoxide sulfur hexafluoride nitrogen trioxide carbon tetrahydride phosphorus trifluoride aluminum chloride
P2O5
I4O9
SF6
NO3
CH4
PF3
AlCl3
Nomenclature FlowchartIs a metal presentas the first element?
Can the metal havemore than oneoxidation state?
Use prefixes(mono, di, tri ...)
Roman numeralsare not needed.
Use Roman numerals
NoNo
NoNo
YesYes
YesYes
Helpful to remember...1. In an ionic compound, the net ionic
charge is zero (criss-cross method)
2. An -ide ending generally indicates a binary compound
3. An -ite or -ate ending means there is a polyatomic ion that has oxygen
4. Prefixes generally mean molecular; they show the number of each atom
Helpful to remember...5. A Roman numeral after the name of
a cation shows the ionic charge of the cation.
Acids
Writing Names and Formulas
Acids Compounds that give off hydrogen ions
when dissolved in water. Must have H in them. Will always be an H next to an anion. The anion determines the name.
Typical Acids and Bases
Acid
HCl HNO3 H2SO4 H3PO4
Base
NaOH KOH Ba(OH)2
Al(OH)3
Naming Acids If the anion attached to hydrogen ends
in -ide, use the prefix hydro- and change -ide to -ic acid
HCl - hydrogen ion and chloride ion hydrochloric acid H2S hydrogen ion and sulfide ion hydrosulfuric acid
Naming Acids If the anion has oxygen in it, no hydro It ends in -ate or -ite Change the suffix -ate to -ic acid HNO3 Hydrogen and nitrate ions
Nitric acid Change the suffix -ite to -ous acid HNO2 Hydrogen and nitrite ions
Nitrous acid
Oxyanion and Oxyacids An ion with oxygen in it is called an
oxyanion. An acid with an oxyanion in it is called
an oxyacid.
Name These
HF H3P
H2SO4
H2SO3
HCN H2CrO4
H3PO4
Hydrofluoric acid
Hydrophosphoric acid
Sulfuric acid
Sulfurous acid
Hydrocyanic acid
Chromic acid
Phosphoric acid
Writing Formulas Hydrogen will always be first Name will tell you the anion Make the charges cancel out Starts with hydro- no oxygen, -ide No hydro, -ic comes from -ate, -ous
comes from -ite
Write Formulas for These hydroiodic acid acetic acid carbonic acid phosphoric acid hydrobromic acid
HI
HC2H3O2
H2CO3
H3PO4
HBr
More Acid Practice
Name and Formula
Name the Formula H2S
H2CrO4
HClO3
H2CO3
HSCN H2SO3
H3PO4
Hydrosulfuric acid
Chromic acid
Chloric acid
Carbonic acid
Thiocyanic acid
Sulfurous acid
Phosphoric acid
Write the Formula Hydroiodic acid Hydrobromic acid Perchloric acid Sulfuric acid Hydrophosphoric acid Hydroselenic acid Chlorous acid
HI
HBr
HClO4
H2SO4
H3P
H2Se
HClO2