Chemical Formulas, and Nomenclature ch 9

1. Chemical Formulas, and Nomenclature ch 9

2. Oxidation Numbers of Monatomic Ions (On periodic table handout) 0 1+ 2+ 3+ 4+ 2- 3- 1- most 2+, but varies

3. Oxidation Numbers and formulas p 66 • Warm up: what does oxidation # tell us about the valence electrons of that atom? • Transition elements have more than one oxidation #, determined by a roman numeral. EX: iron (II) is Fe+2 iron (III) is Fe+3

4. Polyatomic Ions p66 • are made up of two or more atoms. • Polyatomic ions generally have the following endings: “ate” or “ite”

5. Oxidation Numbers & Formulas p66 • The sum of the oxidation numbers in a compound must equal zero. EX: CaCl2 = Ca+2 + Cl- + Cl- 2 positive charges – 2 negative charges = 0

6. Writing Ionic Formulas p66 • the cation ( positive metal ion) is always written before the anion (negative nonmetal ion). There is only one polyatomic cation: NH4+

7. Criss Cross Method of Writing Formulas p66 • Ex. Write the formula for Aluminum and Oxygen: Al +3 and O-2 Al and O Al2O3

8. Criss Cross Method of Writing Formulas p66 EX:Lead (II) & Phosphate Pb+2 and PO4 -3 Pb and PO4 Pb3(PO4)2

9. Nomenclature p68 • Warm up: how do you use the criss cross method to write a formula? • Let’s take a look!

10. Naming Binary Ionic Compounds (2 elements) p68 1. Name of cation (metal) is given first. The name is the same as the element. 2. Name of anion(nonmetal) is given last. The name is the same as the element, but with an “ide” ending.

11. Naming Ionic Compounds p68 EX: Al2O3 Aluminum oxide cation anion

12. Naming Ternary Ionic Compounds p68 • Compounds containing a polyatomic ion. 1. Cation rule from binary applies. 2. Anion takes the name of the polyatomic ion as found on the table. EX: Al2(SO4)3 Aluminum sulfate EX: Mg(OH)2 Magnesium hydroxide

13. Transition metals in formulas p68 • Remember: they can make 2 charges. • Use roman numeral in name. • Ex: CrCl2 Chromium(II) chloride Ex: CuCO3 Copper(II) Carbonate

14. Naming Ionic Compounds EX: AgCl is __________________ Silver chloride HgO is ___________________ Mercury (II) oxide CaBr2 is ___________________ Calcium bromide Cu2O is ___________________ Copper (I) oxide

15. Naming Ionic Compounds EX: SnCO3 is ____________________ Tin(II) carbonate Co(OH)2 is ___________________ Cobalt (II) hydroxide Zn(NO3)2 is __________________ Zinc nitrate KClO3 is ___________________ Potassium chlorate

16. Naming Binary Molecular compounds p70 • Warm up: why does Cobalt (II) hydroxide have a roman numeral in its name? • Name the following compound: • Ba(Na)2 Banana!

17. Naming Binary Molecular Compounds p70 • Composed of two nonmetals • Prefixes are used

18. Naming Binary Molecular Compounds p70 • Say name of 1st element. If there is more than one, give it a prefix. • Say the name of second element and change ending to –ide. Always give it a prefix. 3. The o or a at the end of a prefix is dropped when the element begins with another vowel. EX: monoxide or pentoxide

19. Naming Binary Molecular Compoundsp70 EX: P4O3 *tetraphosphorus trioxide EX: NO *nitrogen monoxide

20. Naming Binary Molecular Compounds EX: SO3 is ____________________ Sulfur trioxide PBr5 is ____________________ Phosphorus pentabromide ICl3 is _____________________ Iodine trichloride H20 is _____________________ Dihydrogen monoxide

21. Naming Binary Molecular Compounds EX: NH3 is ____________________ nitrogen trihydride N2O3 is ____________________ dinitrogen trioxide CO is _____________________ carbon monoxide P2O5 is _____________________ diphosphorouspentaoxide

22. Naming Acids& Bases p 72 • Warm up: what do you know about acids? • Acids are molecular compounds that have a Hydrogen atom bonded to an anion. (H-anion) • Anions can be elements, ending: “-ide” • H + element:  “hydro” -stem “-ic” acid • Ex) HBr=hydrobromic acid

23. Naming acids p72 • Anions can be polyatomics,ending: ”-ite, -ate” • H + polyatomic (-ate) -stem “-ic” acid • Ex) H3PO4= phosphoric acid • H + polyatomic (-ite) -stem “-ous” acid • Ex) H2SO3= sulfurous acid

24. Naming acids p 71 • HBr __________________________ hydrobromic acid • H2SO4 _____________________________________ sulfuric acid • HNO2 _____________________________________ nitrous acid • H3PO4 _____________________________________ phosphoric acid • H2CO3 ____________________________________ carbonic acid • HCl ____________________________ hydrochloric acid

25. Formulas of acids p71 • Nitric acid_______________________ HNO3 • Acetic acid_______________________ HC2H3O2 • Hydrofluoric acid_________________ HF • Sulfurous acid___________________ H2SO3 • Hydrochloric acid_________________ HCl

26. Naming Bases p72 • Say the name of the first element, then add “hydroxide” to end. • Ex) LiOH- lithium hydroxide • Ex) Mg(OH)2- magnesium hydroxide

27. Polyatomic Ions

28. Molecular and Empirical Formulas • The formulas for compounds that exist as molecules are called molecular formulas. EX: Hydrogen peroxide, H2O2, consists of two H atoms and two O atoms. • The atomic ratio of hydrogen peroxide is one to one. • The simplest formula that would indicate this ratio would be HO. This simple formula is an empirical formula.

29. Strange Names for Molecules • ANOL • BUTANOL

30. MORONIC ACID • CRAPINON