Presentation on theme: "UNIT 6 BONDING AND NOMENCLATURE"— Presentation transcript:
1 UNIT 6 BONDING AND NOMENCLATURE LESSON 3NAMING COMPOUNDS
2 NAMING COMPOUNDSChemist name compounds according to the atoms and bonds that compose the compound.
3 Naming Ionic Compounds Name the cation first, then anionMonatomic cation = name of the elementCa2+ = calciumMonatomic anion = root + -ideCl- = chlorideCaCl2 = calcium chloride
4 Naming Ionic Compounds (Metals with multiple oxidation states)some metals can form more than one charge (usually the transition metals)use a Roman numeral in their name:PbCl2 – use the anion to find the charge on the cation (chloride is always 1-)Pb2+ is the lead (II) cationPbCl2 = lead (II) chloride
5 Practice by writing the formula or name as required… Iron (II) PhosphateTin (II) Fluoride(sometimes called Stannous)Potassium SulfideAmmonium ChromateMgSO4FeCl3
7 Naming and Writing Formulas for Molecular Compounds
8 Molecular compounds are… made of just nonmetalssmallest piece is a moleculecan’t be held together by opposite charge attractioncan’t use charges to figure out how many of each atom(there are no charges)
9 Molecular compounds - Formulas are easy! Molecular compounds: the name tells you the number of atoms.Uses prefixes to tell you the exact number of each element present!
12 Naming Molecular Compounds To write the name:1. 1st element: Prefix +name (leastelectronegative).2. 2nd element: Prefix +name (moreelectronegative) change endingto -ideOne exception - we don’t write mono if there is only one of the first element.Normally, we do not have double vowels when writing names (oa oo)
13 Practice by naming these: = dinitrogen monoxide (also called nitrous oxide or laughing gas)N2ONO2Cl2O7CBr4CO2BaCl2= nitrogen dioxide= dichlorine heptoxide= carbon tetrabromide= carbon dioxide(This one will not use prefixes, since it is an ionic compound!)
15 Naming HydratesHydrates are ionic compounds that absorb water into their solid structures.Anhydrous are ionic compounds that are free of water.The name of the hydrated compound must reflect how many water molecules are attached (use prefixes)
16 Practice Naming Hydrates CuSO4 ● 5H2OCopper II Sulfate pentahydrateFe PO4 ● 4H2OIron III Phosphate tetrahydrate
17 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 compound3. An -ite or -ate ending means there is a polyatomic ion that has oxygen4. Prefixes generally mean molecular; they show the number of each atom
18 Helpful to remember...5. A Roman numeral after the name of a cation is the ionic charge of the cation