1. Nomenclature Notes Writing Formulas for Binary Molecular Compounds-those containing 2 nonmetals. Prefix naming system - know theses prefixes: Writing Formulas for Binary Molecular Compounds-those containing 2 nonmetals. Prefix naming system - know theses prefixes: mono – one di – twotri – three tetra – fourpenta - fivehexa – six hepta – sevenocta - eightnona – nine deca – ten

2. Simply write what it says. Ex: phosphorus pentachloride PCl 5 dihydrogen monoxide H 2 O Practice: nitrogen tetrasulfide ______________ carbon dioxide ________________ oxygen monofluoride _____________ trioxygen decanitride ______________ hexafluorine nonasulfide ___________

3. Writing Names for Binary Molecular Compounds Writing Names for Binary Molecular Compounds 1. The less electronegative element is given first. It is given a prefix only if it contributes more than one atom to a molecule of the compound. (All this means is that you will never start with mono-) 2. The second element is named by combining a prefix indicating the number of atoms contributed by the element to the root of the name of the second element and then adding –ide to the end. Common Roots H: hydrC: carbN: nitrO: ox F: florSi: silicP: phosphS: sulf Cl: chlorBr: bromI: iod

4. Practice: CCl 4 ______________________ NF 3 _______________________ PBr 5 _______________________ SF 6 ________________________ SO 3 _______________________ N 2 O________________________

5. Rules for Writing Formulas for Binary Ionic Compounds – these are compounds containing only 1 metal and 1 nonmetal. Rules for Writing Formulas for Binary Ionic Compounds – these are compounds containing only 1 metal and 1 nonmetal. 1. Write the cation (metal ion) first and the anion (nonmetal ion) second. 2. Find the oxidation number of both ions. 3. Crisscross the oxidation numbers. 4. Divide by any common factors. 5. Check your work by making sure the net charge of the compound is zero Hydrogen can either gain, lose, or share an electron depending on the other elements with which it combines.

6. Sodium Chloride Na +1 Cl -1 Overall Charge = 0 Final Formula is NaCl

7. Aluminum Oxide Al +3 O -2 Overall Charge = 0 Final Formula is Al 2 O 3

8. Calcium Oxide Ca +2 O -2 Overall Charge = 0 Final Formula is CaO

9. Practice: Magnesium phosphide____________________ Calcium oxide __________________________ sodium sulfide _____________________ lead (IV) sulfide ____________________ Aluminum nitride _______________________ tin (II) chloride _________________ Potassium fluoride __________________________ Copper (I) phosphide ________________ Copper (II) oxide ___________________________

10. Writing Names for Ionic Compounds Writing Names for Ionic Compounds IUPAC – International Union of Practical and Applied Chemistry is the newest system-this system uses Roman numerals to give the charges or oxidation number of positive ions ONLY if the positive ion has variable charges. This will be the transition metals, lead, and tin

11. A. Rules for Writing Names for Binary Ionic Compounds – these are compounds containing only 1 metal and 1 nonmetal. 1. The correct full name of the cation (metal ion) is written first. (Do not forget about the roman numerals if it is a transition metal ion, lead, or tin) 2. The last syllable in the anion (nonmetal ion) is dropped and –ide is added. Example: NaCl Sodium Chloride Example: CuS Copper (II) Sulfide

12. Practice: MgCl 2 ___________________________ AlI 3 _____________________________ Na 3 P _____________________________ FeN _____________________________ PbCl 2 ________________________________ CuF ____________________________ CuCl 2 _________________________________ Pb0 2 _________________________________ Fe 2 0 3 _____________________________ KI ___________________________________