Download Polyatomic Ions (Memorize for Wednesday, January 31

CHEMICAL NOMENCLATURE
Oxidation Numbers (similar to valence electrons)
Group 1 = +1
Group 2 = +2
Groups 13-18 = group # - 10 for most elements
d-block elements must be looked up (groups 3-12 use roman numerals)
oxidation numbers for ALL compounds MUST equal zero
Metal-Non-metal (binary ionic compounds, only 2 elements)
Metal (cation, +) named first, non-metal (anion, -) named second
Metal name stays unchanged
Non-metal ending changed to –ide
EX –
potassium + iodine  potassium iodide
calcium + oxygen  calcium oxide
Non-metal – non-metal (binary covalent compounds, only 2 elements)
Name least electronegative element first (review periodic trends)
Change ending of second element to –ide
Use prefixes except mono on first element
Crossing over charges = zero
Mono 1
hexa 6
Di 2
hepta 7
Tri 3
octa 8
Tetra 4
nona 9
Penta 5
deca 10
EX – carbon C+4 + chlorine Cl-1x4  carbon tetrachloride
Nitrogen N-3 + oxygen O-2  dinitrogen trioxide
Polyatomic Ions
Ammonium –
Hydroxide –
Acetate –
Carbonate –
Bicarbonate –
Chlorate –
Bromate –
Nitrate –
Sulfate –
Chromate –
Iodate –
Phosphate –
NH4+
OHCH3COO- or CH2COOHCO32HCO3ClO3BrO3NO3SO4-2
CrO4-2
IO3PO4-3
Arsenate Thiosulfate Silicate Oxalate Dichromate Thiocyanate Permanganate Selenate -
AsO43S2O32SiO32C2O42Cr2O72CNSMnO4SeO42-
Rules for polyatomic ions
A = element besides oxygen
O = oxygen
Metal-polyatomic ion
Name metal
AOx = -ate ending of ion (most common form of ion)
AOx+1 = add prefix per-, keep ending –ate
AOx-1 = change –ate ending to –ite
AOx-2 = add prefix hypo-, change –ate ending to –ite
Oxyacids (hydrogen replaces the metal from above)
Polyatomic ions ending in –ate form acids with an –ic ending
EX – H2SO4: sulfate ion changes to sulfuric acid
Polyatomic ions ending in –ite form acids with an –ous ending
EX – HClO2: chlorite ion changes to chlorous acid
The number of hydrogen atoms equals the charge on the polyatomic ion
EX – H3PO4: H+1 x 3 = PO4-3
Transition Metal Compounds (Groups 3-12)
Have multiple oxidation states
Use roman numerals to indicate charge on metal (NOT the number of atoms)
Older method
Higher oxidation number ends with –ic
EX – CuO cupric oxide ( copper has 2+)
Lower oxidation number ends with –ous
EX – Cu2O cuprous oxide (copper has 1+)
Lead – plumbum
Gold – aurum
Mercury – hydrargyrum (little silver)
Iron – ferrum
Tin – stannum
Antimony – stibium
Silver – argentum
Copper - cuprum