1 Chemistry 111 Chapter 6 - Nomenclature

2 Nomenclature – Main Tasks Learn Specific Rule Sets –Ionic Compounds –Covalent Compounds –Transition Metal Cations Learn Oxyanions & Oxyacids –Memorize… Practice –Flash Cards! Keep them in your pocket – pull them out when waiting in lines, during commercials. Collate all of this information…

3 Nomenclature Rules / System of Rules (+ exceptions) Elements Covalent Compounds Monatomic Ions –Regular –Super Sized (super ugly?) Polyatomic Anions –5 “normal” –more & less Acids Formulas of Ionic Compounds Naming Ionic Compounds Common Polyatomic Ions (other)

4 Naming Elements Very Simple – just their names. Diatomic Elements –Remember H, O, N, Cl, Br, I, F all come as diatomic molecules in elemental form –“HONClBrIF” hon-cul-brif –H 2, O 2, …

5 Covalent Compounds 2 non-metals have covalent bonds. Naming system needs to indicate how many of each: CO vs CO 2 Rules: –Use mono-, di-, tri- prefixes (1, 2, 3, …) –End with “-ide” Exception: –Skip mono- prefix with 1 st element –monocarbon dioxide?

6 Monatomic Ions We learned to figure out the charge of an ion formed by each element –except transition metals How do we name them? –Cations: just add “ion” Ca 2+ = “calcium ion”Al 3+ = “aluminum ion” –Anions Add “-ide” and “ion” S 2- = “sulfide ion” Cl - = “chloride ion”

7 Transition Metal Ions Many transition metals have multiple charges (all positive) We have to memorize which are which! (Naming them will be worse…)

8 Common/Important Transition Metal Ions 3B4B5B6B7B8B1B2B3A4A ScTiVCrMnFeCoNiCuZnGaGe YZrNbMoTcRuThPdAgCdInSn LaHfTaWReOsIrPtAuHgTlPb

9 Common/Important Transition Metal Ions 6B7B8B1B2B3A4A Cr 2+ Cr 3+ Fe 2+ Fe 3+ Cu + Cu 2+ Zn 2+ Ag + Sn 2+ Sn 4+ Hg 2 2+ Hg 2+ Pb 2+ Pb 4+

10 Naming Transition Metal Ions with Multiple Charges Stock System –Use a roman numeral with the charge. –Use English Name Fe 3+ = iron (III) ion Fe 2+ = iron (II) ion Sn 4+ = tin (IV) ion Zn 2+ = zinc ion Old System –Use endings to indicate charge –Higher “-ic” –Lower “-ous” –Use latin names Fe 3+ = ferric ion Fe 2+ = ferrous ion Sn 4+ = stannic ion

11 Naming Mercury Hg 2 2+ has +2 spread over 2 mercury atoms –mercury (I) ion, mercurous ion Hg 2+ has +2 on 1 mercury atom –mercury (II) ion, mercuric ion Note that it’s a double exception – we don’t use the latin name!

12 More Nomenclature Polyatomic Anions –5 “normal” –more & less Acids Formulas of Ionic Compounds Naming Ionic Compounds Common Polyatomic Ions (other)

13 Polyatomic Anions These are molecules with negative charge. Inside the anion, bonding is covalent. Outside they form ionic bonds. Be sure to treat the poly-ions as a whole unit! shared electrons lost 1 electon OClO [] - Na +

14 How do we learn all of these? (Table 6.8) 1.Memorize the whole table. 2.Learn a system… (more of Herbelin’s propaganda)

15 Oxyanion System 1.Learn (memorize) the 5 “normal” anions. Element Charge # of oxygens “-ate” 2.Learn how to add/subtract oxygens.

16 5 “Normal” Oxyanions Element# OxygenChargeFormulaName N3NO 3 - nitrate Cl3ClO 3 - chlorate C3-2CO 3 2- carbonate S4-2SO 4 2- sulfate P4-3PO 4 3- phosate

17 Changing the Number of Oxygens The ending shows how many oxygens are on an oxyanion: -ate= normal number -ite=1 fewer oxygens Nitrate NO 3 -, Nitrite NO 2 - Anion keeps the same charge!

18 What about other elements? What is SeO 4 2- ? –“selenate” How do you know it’s “ate”? –Selenium is just below Sulfur. –Use the periodic trend. Atoms below the five normal elements follow the ones above them. Exception: What’s below N?

19 Special Halogen Oxyanions Halogens form 2 extra anions: –per-chlor-ateClO 4 - per = 1 more –chlor-ateClO 3 - “normal” –chlor-iteClO 2 - -ite = 1 less –hypo-chlor-iteClO 1 - hypo-ite = 2 less (ClO - ) Note: –charge stays the same. –No oxygens (Cl - ) = chloride (easy rules)

20 Naming Acids Acids are poly anions with enough H + to balance the charge: AnionNameAcidName CO 3 2- carbonateH 2 CO 3 carbonic acid ClO 3 - chlorateHClO 3 chloric acid ClO 2 - chloriteHClO 2 chlorous acid ClO - hypochloriteHClOhypochlorous acid PO 3 - phosphite H 3 PO 3 phosphorous acid

21 Naming Acids per-ateper-ic -ate-ic -ite-ous hypo-ite-hypo-ous None HClhydrochloric acid

22 Half-Way Hydrogens You can put only some hydrogen (H + ) on your polyatomic ions: –HSO 4 - hydrogen sulfate –HCO 3 - hydrogen carbonate (bicarbonate) –HPO 4 2- monohydrogen phosphate –H 2 PO 4 - dihydrogen phosphate Read your twinkies!

23 Naming Ionic Compounds cation + Space + anion Drop the word Ion Anion will end with either: –ide or –ate/-ite Note: we don’t use any number information on these.

24 Examples Na + Cl - Sodium chloride, NaCl Na + NO 3 - Sodium nitrate, NaNO 3 K + SO 4 2- potassium sulfate, K 2 SO 4 Al 3+ NO 3 - aluminum nitrate, Al(NO 3 ) 3

25 Charge Balance Ionic compounds have to be Neutral Charge Balance gets them to the same number. The math is “least common multiple” We can also “cross” & simplify. Al 3+ NO 3 -1 Al 1 (NO 3 ) 3  Al(NO 3 ) 3

26 Other Polyatomic Ions Cations: –NH 4 + ammonium ion –H 3 O + hydronium ion Anions: –CH 3 COO - or C 2 H 3 O 2 - acetate ion –CN - cyanide ion –SCN - thiosyanate ion (thio = sulfur = smelly) –O 2 2- peroxide ion (weird: oxygen = -1, not –2)