Chapter 5
Naming Compounds
Writing Formulas
Systematic Naming
lThere are too many compounds toremember the names of them all.
lCompound is made of two or moreelements.
lPut together atoms.
lName should tell us how many andwhat type of atoms.
Periodic Table
lMore than a list of elements.
lPut in columns because of similarproperties.
lEach column is called a group.
Metals
Metals
lLuster – shiny.
lDuctile – drawn into wires.
lMalleable – hammered into sheets.
lConductors of heat and electricity.
Non-metals
lDull
lBrittle
lNonconductors- insulators
Atoms and ions
lAtoms are electrically neutral.
lSame number of protons and electrons.
lIons are atoms, or groups of atoms, witha charge.
lDifferent numbers of protons andelectrons.
lOnly electrons can move.
lGain or lose electrons.
Anion
lA negative ion.
lHas gained electrons.
lNon metals can gain electrons.
lCharge is written as a super script onthe right.
F-1
Has gained one electron
O-2
Has gained two electrons
Cations
lPositive ions.
lFormed by losing electrons.
lMore protons than electrons.
lMetals form cations.
K+1
Has lost one electron
Ca+2
Has lost two electrons
Compounds
lFollow the Law of Definite Proportion.
lHave a constant composition.
lHave to add the same number of atomsevery time.
lTwo types.
Two Types of Compounds
Molecular compounds
lMade of molecules.
lMade by joining nonmetal atomstogether into molecules.
Two Types of Compounds
Ionic Compounds
lMade of cations and anions.
lMetals and nonmetals.
lThe electrons lost by the cation aregained by the anion.
lThe cation and anions surround eachother.
Chemical Formulas
lShows the kind and number of atoms inthe smallest piece of a substance.
lMolecular formula- number and kinds ofatoms in a molecule.
lCO2
lC6H12O6
Charges on ions
lFor most of the Group A elements, thePeriodic Table can tell what kind of ionthey will form from their location.
lElements in the same group havesimilar properties.
lIncluding the charge when they areions.
+2
+1
+3
-3
-2
-1
What about the others?
lWe have to figure those out some otherway.
lMore on this later.
Naming ions
lWe will use the systematic way.
lCation- if the charge is always the same(Group A) just write the name of themetal.
lTransition metals can have more thanone type of charge.
lIndicate the charge with romannumerals in parenthesis.
Name these
lNa+1
lCa+2
lAl+3
lFe+3
lFe+2
lPb+2
lLi+1
Write Formulas for these
lPotassium ion
lMagnesium ion
lCopper (II) ion
lChromium (VI) ion
lBarium ion
lMercury (II) ion
Naming Anions
lAnions are always the same.
lChange the element ending to – ide
lF-1 Fluorine
Naming Anions
lAnions are always the same.
lChange the element ending to – ide
lF-1 Fluorin
Naming Anions
lAnions are always the same
lChange the element ending to – ide
lF-1 Fluori
Naming Anions
lAnions are always the same
lChange the element ending to – ide
lF-1 Fluor
Naming Anions
lAnions are always the same
lChange the element ending to – ide
lF-1 Fluori
Naming Anions
lAnions are always the same
lChange the element ending to – ide
lF-1 Fluorid
Naming Anions
lAnions are always the same
lChange the element ending to – ide
lF-1 Fluoride
Name these
lCl-1
lN-3
lBr-1
lO-2
lGa+3
Write these
lSulfide ion
liodide ion
lphosphide ion
lStrontium ion
Polyatomic ions
lGroups of atoms that stay together andhave a charge.
lYou already memorized these
lAcetate C2H3O2-1
lNitrate NO3-1
lNitrite NO2-1
lHydroxide OH-1
lPermanganate MnO4-1
lCyanide CN-1
Polyatomic ions
lSulfate SO4-2
lSulfite SO3-2
lCarbonate CO3-2
lChromate CrO4-2
lDichromateCr2O7-2
lPhosphate PO4-3
lPhosphite PO3-3
lAmmonium NH4+1
Ions in Ionic Compounds
Naming Binary Ionic Compounds
lBinary Compounds - 2 elements.
lIonic - a cation and an anion.
lTo write the names just name the twoions.
lEasy with Representative elements.
lGroup A
lNaCl = Na+ Cl- = sodium chloride
lMgBr2 = Mg+2 Br- = magnesium bromide
Naming Binary Ionic Compounds
lThe problem comes with the transitionmetals.
lNeed to figure out their charges.
lThe compound must be neutral.
lsame number of + and – charges.
lUse the anion to determine the chargeon the positive ion.
Naming Binary Ionic Compounds
lWrite the name of CuO
lNeed the charge of Cu
lO is -2
lcopper must be +2
lCopper (II) chloride
lName CoCl3
lCl is -1 and there are three of them = -3
lCo must be +3 Cobalt (III) chloride
Naming Binary Ionic Compounds
lWrite the name of Cu2S.
lSince S is -2, the Cu2 must be +2, soeach one is +1.
lcopper (I) sulfide
lFe2O3
lEach O is -2 3 x -2 = -6
l3 Fe must = +6, so each is +2.
liron (III) oxide
Naming Binary Ionic Compounds
lWrite the names of the following
lKCl
lNa3N
lCrN
lSc3P2
lPbO
lPbO2
lNa2Se
Ternary Ionic Compounds
lWill have polyatomic ions
lAt least three elements (3 capitalletters)
lname the ions
lNaNO3
lCaSO4
lCuSO3
l(NH4)2O
Ternary Ionic Compounds
lLiCN
lFe(OH)3
l(NH4)2CO3
lNiPO4
Writing Formulas
lThe charges have to add up to zero.
lGet charges on pieces.
lCations from name of table.
lAnions from table or polyatomic.
lBalance the charges by addingsubscripts.
lPut polyatomics in parenthesis.
Writing Formulas
lWrite the formula for calcium chloride.
lCalcium is Ca+2
lChloride is Cl-1
lCa+2 Cl-1 would have a +1 charge.
lNeed another Cl-1
lCa+2 Cl2-1
lflip the charges!
Write the formulas for these
lLithium sulfide
ltin (II) oxide
ltin (IV) oxide
lMagnesium fluoride
lCopper (II) sulfate
lIron (III) phosphide
lgallium nitrate
lIron (III) sulfide
Write the formulas for these
lAmmonium chloride
lammonium sulfide
lbarium nitrate
Things to look for
lIf cations have (), the number is theircharge.
lIf anions end in -ide they are probablyoff the periodic table (Monoatomic)
lIf anion ends in -ate or -ite it ispolyatomic
Molecular Compounds
Writing names and Formulas
Molecular compounds
lmade of just nonmetals
lsmallest piece is a molecule
lcan’t be held together because ofopposite charges.
lcan’t use charges to figure out howmany of each atom
Easier
lIonic compounds use charges todetermine how many of each.
–Have to figure out charges.
–Have to figure out numbers.
lMolecular compounds name tells youthe number of atoms.
lUses prefixes to tell you the number
Prefixes
l1 mono-
l2 di-
l3 tri-
l4 tetra-
l5 penta-
l6 hexa-
l7 hepta-
l8 octa-
Prefixes
l9 nona-
l10 deca-
lTo write the name write two words
Prefixes
l9 nona-
l10 deca-
lTo write the name write two words
Prefix
name
Prefix
name
-ide
Prefixes
l9 nona-
l10 deca-
lTo write the name write two words
lOne exception is we don’t write mono- ifthere is only one of the first element.
Prefix
name
Prefix
name
-ide
Prefixes
l9 nona-
l10 deca-
lTo write the name write two words
lExceptions:
lwe don’t write mono- if there is only one ofthe first element.
lNo double vowels when writing names (oaoo)
Prefix
name
Prefix
name
-ide
Name These
lN2O
lNO2
lCl2O7
lCBr4
lCO2
lBaCl2
Write formulas for these
ldiphosphorus pentoxide
ltetraiodide nonoxide
lsulfur hexaflouride
lnitrogen trioxide
lCarbon tetrahydride
lphosphorus trifluoride
laluminum chloride
Acids
Writing names and Formulas
Acids
lCompounds that give off hydrogen ionswhen dissolved in water.
lMust have H in them.
lwill always be some H next to an anion.
lThe anion determines the name.
Naming acids
lIf the anion attached to hydrogen isends in -ide, put the prefix hydro- andchange -ide to -ic acid
lHCl - hydrogen ion and chloride ion
lhydrochloric acid
lH2S hydrogen ion and sulfide ion
lhydrosulfuric acid
Naming Acids
lIf the anion has oxygen in it
lit ends in -ate of -ite
lchange the suffix -ate to -ic acid
lHNO3 Hydrogen and nitrate ions
lNitric acid
lchange the suffix -ite to -ous acid
lHNO2 Hydrogen and nitrite ions
lNitrous acid
Name these
lHF
lH3P
lH2SO4
lH2SO3
lHCN
lH2CrO4
Writing Formulas
lHydrogen will always be first
lname will tell you the anion
lmake the charges cancel out.
lStarts with hydro- no oxygen, -ide
lno hydro, -ate comes from -ic, -itecomes from -ous
Write formulas for these
lhydroiodic acid
lacetic acid
lcarbonic acid
lphosphorous acid
lhydrobromic acid