11/24/09

Hw assignment Monday night- fill out the bingo cards Dr. B is giving us, fill it in with the ions of charts 1 and 2 from chapter 7. We play bingo on Tuesday- winners get candy!!!!

Naming Binary Ionic Compounds

The Stock System of Nomenclature

• Some elements such as iron, form two or more cations with different charges
• To distinguish the ions formed by such elements, scientists use the stock system of nomenclature.
• The system uses a Roman numeral to indicate an ion's charge.

Compounds Containing Polyatomic Ions

• Many common polyatomic ions are oxyanions polyatomic ions that contain oxygen.
• Some elements can combine with oxygen to form more that one type of oxyanion
• Ex: nitrogen can form WO-3 or NO-2
• The name of the ion with the greater number of oxygen atoms end in -ate. The name of the ion with the smaller number of oxygen atons ends in -ite.

NO-3 NO-2

nitrate nitrite

• Some elements can form more than two types of oxyanions.
• Ex: Chlorine can form ClO-, ClO-2, ClO-3, ClO-4
• In this case, an anion that has one fewer oxygen atom than the -ite anion has is given the prefix -hypo.
• An anion that has one more oxygen atom thatn the -ate anion has is given the prefix per-.

ClO- ClO-2 Cl0-3 ClO-4

hypochlorite chlorite chlorate perchlorate

DO NOT SAY DIMERCURY, CALL IT MERCURY 1 OR 2.

Naming Compounds with Polyatomic Ions

• Name the cation
• Name the anion
• Name the salt- names of cation and anion

YOU WANT POLYATOMIC IONIC COMPOUNDS TO BE ELECTRICALLY NEUTRAL

YOU CANNOT MOVE ATOMS FROM 1 POLYATOMIC ION TO THE NEXT

Naming Binary Molecular Compounds

• Unlike ionic compounds, molecular compounds are composed of individual covalently bonded units, or molecules.
• As with ionic compounds, there is also a stock system for naming molecular compounds.
• The old system of naming molecular compounds is based on the use of prefixes.
• Ex: CCl4- carbon tetrachloride (tetra=4)
• Ex: CO-carbon monoxide( mon=1)
• Ex: CO2- carbon dioxide ( di=2)

Covalent -Network Compounds

• Same covalent............ (TO BE CONTINUED!!)