Naming+Ionic+Compounds

__Naming Ionic Compounds__
__**IONIC COMPOUND**__: A compound, usually between a metal and a nonmetal, that is the result of ionic bonding

The way an ionic compound is named depends on its valency (charge).


 * ~ Positively charged ion are called cations**

Cations formed from nonmetal atoms have names that end in -ium. NH4+ --> ammon ium ion


 * ~ Negatively charged ions are called anions**

Monoatomic (one-atom) anions have names formed by replacing the ending with -ide. O2- --> ox ide

Polyatomic (many-atom) anions containing oxygen have names ending in -ate or -ite. The ending -ate is used for the most common oxyanion of an element and the ending -ite is used for an oxyanion that has the same charge but one less O atom. NO3- --> nitr ate ion SO4 2- -->sulf ate ion NO2- --> nitr ite ion SO3 2- -->sulf ite ion


 * __~__ __The cations are always named first__**

__**IONIC COMPOUNDS CONTAINING IONS OF ELEMENTS**__  H2 S CATION: H+ is named as hydrogen ANION: S2- is named as sulfide Name of compound is hydrogen sulfide <-- Negatively charged elements have the suffix -ide

Hydrogen has a charge of 1+ and sulfur has a charge of 2-. When writing the formulas you cross the charges and it becomes H2S. You do not need to add the 1 after S(sulfur). The name of this formula would be Hydrogen Sulfide.

__Another example:__ CaCl2 --> Calcium Chlor ide

The ammonium ion (NH4+) is an example of a polyatomic cation. **  Ca CO3 CATION: Ca2+ is named as calcium (Group II metal) ANION: CO32- is named as carbonate Name of compound is calcium carbonate <-- When naming a poly-atomic ion the suffix remains the same.
 * __IONIC COMPOUNDS CONTAINING POLYATOMIC IONS:__

Calcium has a charge of 2+ and carbonate has a charge of 2-. Because the charges cancel out the formula would just be CaCO3. The name of this ionic compound would be Calcium Carbonate.

__Another example:__ Al(NO3)3 --> Aluminum Nitr ate

__**ISLAND OF CERTAINTY AND WHEN TO GO ROMAN:**__
 * An ion with only one possible charge keeps its name unchanged.

Examples: **Group I metals (charge 1+), Group II metals (charge 2+), Aluminium (charge 3+), Zinc (charge 2+), Silver (charge 1+) Cadmium (charge 2+)**
 * Island of Certainty: Al 3+, Zn2+, Cd2+, Ag1+


 * An ion with a number of possible charges has its name followed by Roman Numerals in brackets that represent the charge.

Example:** Copper+ = Cu (I), Copper2+ = Cu (II) Cu(ClO4)2 --> copper (II) perchlorate





http://www.webschool.org.uk/revision/nacl.jpg http://www.ausetute.com.au/namiform.html Chemistry, T__he Central Science__- ninth edition. [] [|www.saskschools.ca/curr_content/chem30_05/appendix/glossary.htm]