Naming Compounds Writing Formulas Chapters 8 & 9 Naming Compounds Writing Formulas

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.

Periodic Table More than a list of elements. Put in columns because of similar properties. Each column is called a group.

Representative Elements The group A elements

Metals

Metals Luster – shiny. Ductile – drawn into wires. Malleable – hammered into sheets. Conductors of heat and electricity.

Transition Metals The Group B elements

Non-Metals Dull Brittle Nonconductors- insulators

Metalloids or Semimetals Properties of both Semiconductors

Atoms and Ions Atoms are electrically neutral. Same number of protons and electrons. Ions are atoms, or groups of atoms, with a charge. Different numbers of protons and electrons. Only electrons can move. Gain or lose electrons.

F-1 O-2 Anion A negative ion. Has gained electrons. Non metals can gain electrons. Charge is written as a super script on the right. F-1 Has gained one electron O-2 Has gained two electrons

K+1 Ca+2 Cations Positive ions. Formed by losing electrons. More protons than electrons. Metals form cations. K+1 Has lost one electron Ca+2 Has lost two electrons

Naming Compounds Writing Formulas 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. 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 Compounds 2 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 Ionic Molecular Smallest Piece Formula Unit Molecule Types of Elements Metal and Nonmetal Nonmetals Solid, Liquid or Gas State Solid Melting Point High >300ºC Low <300ºC

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”

Ionic Compounds This formula represents not a molecule, but a formula unit The smallest whole number ratio of atoms in an ionic compound. Ions surround each other so you can’t say which is hooked to which. (p. 140)

Charges on Ions For most of the Group A elements, the periodic table can tell what kind of ion they will form based on their location. Elements in the same group have similar properties. Including the charge when they become ions.

+1 +2 +3 -3 -2 -1

What about the others? Groups 4A and 8A do not usually form ionic bonds (in fact, Group 8A rarely forms compounds!) Many transition metals have more than one common ionic charge

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 Charges Transition 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 Na+1 Ca+2 Al+3 Fe+3 Fe+2 Pb+2 Li+1

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) Cl-1 N-3 Br-1 O-2 Ga+3

Write These sulfide ion iodide ion phosphide ion strontium ion S-2 I-1 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 Ammonium NH4+1 Sulfate SO4-2 Sulfite SO3-2 Carbonate CO3-2 Chromate CrO4-2 Dichromate Cr2O7-2 Phosphate PO4-3 Phosphite PO3-3

Common Polyatomic Ions

We’ve named the ions, so now it is time to name the compounds! 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 Charge Na+ & O-2 Na+x O-2y x(+1) + y(-2) = 0 find the smallest common factor Na2O Ca+2 & N-3 x(+2) + y(-3) = 0 Ca3N2

Balancing Charges How 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.

Naming Ionic Compounds Many 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 Examples FeCl2 iron(II) chloride FeCl3 iron(III) chloride SnS tin(II) sulfide SnS2 tin(IV) sulfide AgCl silver chloride CdS cadmium sulfide Note Some transition metals only have a single state so the roman numeral may be omitted. Some main group metals, with high atomic number have 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 Li2S SnO SnO2 MgF2 CuSO4 FeP GaNO3 Fe2S3 lithium sulfide tin (II) oxide tin (IV) oxide magnesium fluoride copper (II) sulfate iron (III) phosphide gallium (I) nitrate iron (III) sulfide

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

Writing Names and Formulas 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 Prefix name Prefix name -ide 9 nona- 10 deca- To write the name, write two words with Prefix name Prefix name -ide

Prefixes Prefix name Prefix name -ide 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 Prefix name Prefix name -ide 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 Flowchart Is a metal present as the first element? No Use prefixes (mono, di, tri ...) Yes Can the metal have more than one oxidation state? No Roman numerals are not needed. Yes Use Roman numerals

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.

Writing Names and Formulas 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 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.

Acids If the second element ends in -ide, name the acid hydro - root - ic acid HCN = hydrogen cyanide = hydrocyanic acid If the second element ends in -ite, name the acid root - ous acid H2SO3 = hydrogen sulfite = sulfurous acid

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