Naming Polyatomic Ions and Acids Oxyanions n Oxyanions

Naming Polyatomic Ions and Acids

Oxyanions n Oxyanions- negative ions containing oxygen. n These have the suffix “-ate” or “-ite” n “-ate” means it has more oxygen atoms bonded, “-ite” has less n For example n SO 42 - sulfate n SO 32 - sulfite

Oxyanions n Oxyanions may contain the prefix “hypo- ”, less than, or “per-”, more than. n For example n Cl. O 4 Perchlorate n Cl. O 3 Chlorate n Cl. O 2 Chlorite n Cl. OHypochlorite

Acids n Certain compounds produce H+ ions in water, these are called acids. n You can recognize them because the neutral compound starts with “H”. n For example HCl, H 2 SO 4, and HNO 3. n All acids are like ionic compounds but the metal is replaced with H+ n It will be H +halogens or H + polyatomic ions

Naming acids n Does it contain oxygen? n If it does not, it gets the prefix “hydro-” and the suffix “-ic acid” n HCl n Hydrochloric acid n HF n Hydrofluoric acid n HCN n Hydrocyanic acid

Naming Acids n If it does contain an oxyanion, then replace the ending. n If the ending was “–ate”, add “-ic acid” n If the ending was “–ite”, add “-ous acid” n H 2 SO 4 Sulfuric Acid n H 2 SO 3 Sulfurous Acid

Examples n HNO 3 n Nitric acid n HCl. O n Hypochlorous acid n HCl. O 2 n Chlorous acid n HCl. O 4 n Perchloric acid n H 2 CO 3 n Carbonic acid n HF n Hydrofluoric acid

Nomenclature (naming) of Covalent compounds

Determining the type of bond n First, determine if you have an ionic compound or a covalent compound. n A metal and a nonmetal will form an ionic bond. n Compounds with Polyatomic ions form ionic bonds. n Nonmetals bonding together or Nonmetals and a metalloid form covalent bonds.

Covalent bonding is very similar to ionic naming n You always name the one that is least electronegative first (furthest from fluorine) n Most electronegative last, and gets the suffix “-ide”.

Covalent bonding is very different from ionic naming n Ionic names ignored the subscript because there was only one possible ratio of elements. n Covalent gives several possibilities so we have to indicate how many of each atom is present in the name

Prefixes you have to know prefix meaning *mono- 1 hex- 6 di- 2 hept- 7 tri- 3 oct- 8 tetr- 4 non- 9 pent- 5 dec- 10 * the first atom named does not get the prefix “mono-”, it just keeps its original name!

Examples n CO n carbon monoxide n CO 2 n carbon dioxide n NI 3 n nitrogen triiodide n P 4 O 6 n tetraphosphorus hexoxide

Continuing n I 4 O 9 n tetriodine nonoxide n S 2 F 10 n disulfur decafluoride n IF 7 n Iodine heptafluoride n Si 2 Cl 6 n disilicon hexachloride

Something to be wary of n Many chemicals have “common names” because they have been in use for so long n like H 2 O 2 n following naming rules it is… n dihydrogen dioxide n commonly it is hydrogen peroxide.

Homework n Go to http: //www. DHMO. org and write a 2 paragraph reaction to the site citing actual information presented in the site. Not just an angry rant, but an intelligent opinion. n Pay attention to what you just learned! n Due by next Wednesday