2. Chapters 4 & 5 – Formation of Compounds Naming Compounds And Writing Formulas

4. Compound Name of Metal cation (first element) Name of non metal anion (second element) Name of compound Na 2 OSodium ion Na 1+ Oxide ion O 2- Sodium oxide KF BaCl 2 Al 2 S 3 Ca 3 N 2 LiBr

5. Ionic Compounds Metal bonded to a non-metal (NaCl) –Metals = cations –Non-metals = anions

6. Naming Ionic Compounds 1.Name the metal first (cation) –The cation name simply is the name of the element 2.Name the non-metal next (anion) –Anion name is non-metal name with –ide suffix (oxygen  oxide)

7. KCl Potassium chloride Li 2 O Lithium oxide NaBr Sodium bromide

8. Writing Ionic Formulas 1.Write the symbol for the metal first with the charge 2.Write the symbol for the nonmetal next with the charge 3.Crisscross the number of the charge 4.All compounds are neutral, so the charges must add to ZERO

9. EXAMPLES Aluminum sulfide Al +3 S -2 Al 2 S 3 Calcium chloride Ca +2 Cl -1 CaCl 2

10. Magnesium oxide Mg +2 and O -2 Mg 2 O 2 this can be reduced to MgO

11. Naming when the metal forms more than one charge Look at the Periodic Table – some elements have more than one charge – Transition Metals Ex: Copper +1 or +2 Roman Numerals are used to indicate the charge. Copper (I) or Copper (II) Cu +1 or Cu +2

12. Writing Copper (II) chloride CuCl 2

13. Naming Determine the charge by working backwards Write the charge in roman numerals in the name CuF 2 Copper is either +1 or +2 charge In this case it is +2 since there are two Fluorine atoms for every one copper (F is always -1 charge) Copper (II) Fluoride

14. Examples CrCl 3 Chromium (III) chloride

15. EXAMPLES Fe (III) and CO 3 Fe +3 (CO 3 ) -2 Fe 2 (CO 3 ) 3

16. Metal + Polyatomic Polyatomic Ion – Groups of nonmetal atoms bonded together that carry a charge. Always include parenthesis around these ions End in –ate or –ite –Exceptions – Hydroxide, Cyanide, Ammonium Found on the back of your periodic table

17. Naming Metal bonded to a polyatomic ion Al 2 (SO 4 ) 3 –Name the metal –Name the polyatomic ion as it appears on the back of your periodic table

18. MgSO 4 Magnesium sulfate CaCO 3 Calcium carbonate Sn(OH) 4 Tin (IV) hydroxide

19. Writing Write the symbol for the metal and charge Write the polyatomic ion in parenthesis and with charge Criss cross the charges

20. Magnesium hydroxide Sodium sulfate

21. Naming Molecular Compounds Two non-metals bonded together; shared bond of electrons Example: CO 2 = carbon dioxide Prefixes are used to express the number of each element The second nonmetal ends in –ide Never reduce

22. Prefixes (1) mono, (2) di, (3) tri, (4) tetra, (5) penta,(6) hexa,(7) hepta, (8) octa,(9) nona,(10) deca The prefix mono- is not used with the first named element Use the back of your periodic table to help you

23. Name the following: SO 3 Sulfur trioxide N2O5N2O5 dinitrogen pentoxide C 2 Br 6 dicarbon hexabromide

24. Write the correct formula: pentacarbon decahydride C 5 H 10 tetrasulfur heptoxide S4O7S4O7 carbon monobromide CBr