2.8 – Naming Inorganic

CompoundsAP Chemistry Summer Homework

Chapter 2

Naming• There are almost an infinite number of ways in

which element can combine in order to make compounds

• Therefore, a systematic method is used so that we can easily name all compounds

• We will focus on naming inorganic (all non-carbon containing) compounds in this lecture

Names and Formulas of Ionic Compounds: Cations

1. Cations formed from metal atoms have the same name as the metalo E.g.: Na+ is a sodium ion, Zn+2 is a zinc ion, etc.

2. If a metal can have multiple charges, the positive charge is indicated by a Roman numeral in parentheses following the name of the metal.o E.g.: Fe2+ = iron (II) ion, Cu+3 = copper (III) iono Iron, cobalt, copper, tin, and lead are the most

common metals that have multiple charges

REMEMBER – MEMORIZE YOUR POLYATOMIC IONS!

Names and Formulas of Ionic Compounds: Anions

1. The names of elements that are anions are formed by adding –ide to the end of the nameo Cl- = Chloride iono Br-

= Bromide iono O2- = Oxide ion

Names and Formulas of Ionic Compounds:

Anions2. Polyatomic ions that contain oxygen have names ending in either –ate or –ite

-ate ending polyatomic have

more oxygens than –ite ones!

Names and Formulas of Ionic Compounds:

Anions• Sometimes oxygen binds to the same ion with

increasing amount of oxygens (e.g. ClO4-, ClO3

-, etc.)

• These come in 4’s and the pattern is always:o Per_____ate = 4 oxygenso _______ate = 3 oxygenso _______ite = 2 oxygenso Hypo______ite = 1 oxygen

• Example:o ClO4

- = Perchlorate, ClO3- = Chlorate, ClO2

- = Chlorite, ClO- = Hypochlorite

Names and Formulas of Ionic Compounds:

Anions3. Anions derived by adding H+ to an oxygen containing anions have the prefix of hydrogen or dihydrogen based on the number of H+ in the anion

Naming Ionic Compounds

• To name ionic compounds, you always name the cation and then the anion.

Class Example

Name the following compounds:1. CaCl22. Ba(OH)2

3. Sodium hydroxide

Try It Out!1. K2SO4

2. FeCl33. Cobalt (II) Nitrate

Names and Formulas for Acids

• Recall, acids are compounds that donate a hydrogen ion to solution.

• Acids are named differently than other compounds• Two rules when naming acids:

1. Acids containing anions that are only single elements are named by changing the –ide prefix on the anion to –ic and adding hydro in front of the anion and then adding acid at the end.• E.g. HCl is hydrochloric acid

2. Acids containing polyatomic ions are named by changing –ate to –ic and –ite to –ous on the anion and then adding acid at the end

Class Example

1. HBr2. H2SO4

3. HClO2

Try It Out!1. HNO3

2. HF

Naming Covalent Molecules (Non-Acids)• The process for naming covalent inorganic

compounds requires the following rules:1. The name of the element furthest

left on the Periodic Table is writtenfirst

2. If both elements are in the same group, the larger one is written 1st

3. The name of the second element is given an –ide ending4. Greek prefixes are used to show the number of atoms

Prefix Meaning

Mono- 1Di- 2Tri- 3

Tetra- 4Penta- 5Hexa- 6Hepta- 7Octa- 8Nona- 9Deca- 10

Class Example

1. SiBr4

2. Disulfur dichloride3. NH3

Try It Out!1. N2O2. Tetraphosphorus hexasulfide