Unit 4: Chemical Nomenclature Section 2: Stock System Ion Compounds

Binary Compounds with Stock System Ions Stock System Ion - ion that can have more than one possible charge –Example: Fe 2+ and Fe 3+ Most transition metals are stock system ions!

Naming Stock System Ion Compounds Same method as basic binary compounds, except we need to know WHICH cation is being used We designate this with a roman numeral in parentheses behind the metal name Roman numerals are used to specify the charge: –1  I –2  II –3  III –4  IV - 5  V

It makes a difference!!! Copper (I) chloride Copper (II) chloride

BUT… HOW DO I FIGURE OUT WHICH ION WENT INTO THE COMPUND?!?!?! DON’T FREAK OUT! WE’LL MAKE IT THROUGH!

Reverse Criss-Cross! Remember, in the formula, the bottom numbers CAME from the criss-crossed charges. So REVERSE criss-cross to get the charges… –CaCl 2  Ca 2+ and Cl 1-

Examples of Stock System Compounds Tin and Chlorine –Formula 1: SnCl 2  Sn 2+ and Cl 1- –Name 1: Tin (II) chloride -Formula 2: SnCl 4  Sn 4+ and Cl 1- -Name 2: Tin (IV) chloride

Examples of Stock System Compounds Copper and Nitrate –Formula 1: CuNO 3  Cu + and NO 3 1- –Name 1: Copper (I) nitrate –Formula 2: Cu(NO 3 ) 2  Cu 2+ and NO 3 1- –Name 2: Copper (II) nitrate

Let’s practice!!!