70 likes | 191 Views
Write the formula. Metal ( cation )first (roman) indicates metal charge Anion next, use first on PT for “ides” use half sheet for polyatomics Cation charge becomes anion subscript and vice versa(“ criss -cross” charges) Reduce as necessary by greatest common factor. Sodium Chloride.
E N D
Write the formula Metal (cation)first (roman) indicates metal charge Anion next, use first on PT for “ides” use half sheet for polyatomics Cation charge becomes anion subscript and vice versa(“criss-cross” charges) Reduce as necessary by greatest common factor
Sodium Chloride Na+ Cl- NaCl
Magnesium fluoride Mg2+ F- MgF2
calcium hydroxide Ca2+ OH- Ca(OH)2
Name a formula Metal (cation)first, just the name no prefix, no suffix IFF!!! PT shows more than one charge for the metal, Use (roman) to indicate metal charge Cation charge = (anion charge)X(anion subscript)/(cation subscript) Anion name next
Fe3(PO4)2 Iron Iron ( ) Iron ( ) Phosphate (3)x(2)/3=2 Iron (II) Phosphate +2 +3 Fe There’s two oxidation states, so we’ll need roman numerals. Anion subscript is 2 Anion charge is 3- Cation subscript is 3 Roman = 2
Parenthesis • Use around polyatomics when there’s more than one in the molecule!