Starter 12/5

1. Starter 12/5 CCl4 MgCl2 • Guess at the names for these two compounds • Predict whether each is ionic or molecular compound • Understanding the difference in bonding, explain what the formula means for each. Draw pictures to help.

2. Ch. 7: Chemical Formulas and Compounds 7.1 Chemical Names and Formulas

3. Chemical Formulas • molecular compound • number of atoms of each element contained in a single molecule of the compound • NO2, CH2Cl2,

4. Chemical Formulas • ionic compound • represents one unit • simplest ratio of the compound’s anions and cations • MgO, Mg(OH)2, NH4Br

5. Monatomic Ions • ions formed from a single atom • Not all representative elements easily form ions • Some atoms form covalent bonds instead • Others form ions without noble gas configurations • d and p-block metals • many form 2+ or 3+, some +1 or +4 • listed on back of periodic table

6. Monatomic Ions • type of ion can be determined by looking at the number of valence electrons in the neutral atom • atom is more stable with a full shell • zero valence • eight valence • determine which is easier for the atom to achieve

7. cation positive if the atom loses electrons B Mg Rb Al Na anion negative if the atom gains electrons N F S O Br Monatomic Ions

8. cations positive ion written first in formula by element’s name add a Roman Numeral if it can form more than 1 type of ion that is called the STOCK SYSTEM anions negative ion written second in formula by element’s root name + -ide ending Naming Monatomic Ions

9. Practice: Monatomic Ions • Identify the ion created by each atom and give the name for it: • Ga • Se • Ca • I • N • Li

10. Binary Ionic Compounds • compounds made of two different ions • Crossing Over • write two ion types with correct charges • make the anion’s charge, the cation’s subscript • make the cation’s charge, the anion’s subscript • simplify the ratio if possible • combine the names of the two ions

11. Al and O Al3+ O2- Al2O3 aluminum oxide Mg and Br Mg2+ Br1- MgBr2 magnesium bromide Cu and Br Cu2+ Br1- CuBr2 copper (II) bromide OR Cu1+ Br1- CuBr copper (I) bromide Practice Naming

12. iron (III) sulfide Fe3+ S2- Fe2S3 cadmium oxide Cd2+ O2- Cd2O2 CdO potassium nitride K1+ N3- K3N tin (IV) sulfide Sn4+ S2- Sn2S4 SnS2 Practice Writing Formulas

13. Cmpds with Polyatomic Ions • the cation or anion could be a group of covalently bonded atoms instead of one atom • most polyatomic ions are oxyanions: • polyatomic ions containing oxygen • more than one polyatomic anion can exist for one element • sulfate ion: SO42- sulfite ion: SO32-

14. KNO3 potassium nitrate from K1+ and NO31- Cu(OH)2 copper (II) hydroxide from Cu2+ and OH1- [NH4]Br ammonium bromide from NH41+ and Br1- CaSO4 calcium sulfate from Ca2+ and SO42- Practice Naming

15. sodium permanganate Na1+ MnO41- Na(MnO4) iron (II) chlorite Fe2+ ClO21- Fe(ClO2)2 ammonium acetate NH41+ CH3COO1- NH4CH3COO calcium carbonate Ca2+ CO32- CaCO3 Practice Writing Formulas

16. Starter 1/6 • Write the formula for • barium nitrate • zinc phosphate

17. Traditional vs. Stock • Stock System • using Roman Numerals in names of metal ions with more than one charge • more important and used more often • Traditional • add –ic or –ous ending to metal name • lower charge: -ous, higher charge: -ic • Shown on the chart below Stock System chart

18. stannous chloride SnCl2 chromic sulfate Cr2(SO4)3 plumbic nitrate Pb(NO3)4 aurous oxide Au2O ferric phosphate FePO4 cuprous chlorate CuClO3 Examples

19. CuCl2 cupric chloride Pt3(PO4)2 plantinous phosphate AuBr aurous bromide PbO plumbous oxide SnO2 stannic oxide Fe(NO3)2 ferric nitrate Examples