22.3 Notes Continued

Objectives

Write formulas and names for ionic compounds

Step By Step – Naming Compounds

1. Write the name of the positive ion Transition metals - determine

the oxidation number of the ion from the formula of the compound.

Write the charge of the positive ion using roman numerals in parentheses after the ion’s name

Naming Continued

2. Write the root name of the negative ion. The root is the first part of the element’s name from the periodic table

3. Add the ending -ide to the root.

The table lists several elements and their -ide counterparts

F-1 FluorineF-1 Fluoride

Name These

Na+1

Al+3

Fe+3

Fe+2

Li+1

N-3 Br-1 O-2 Ga+3

Subscripts

• Do not become part of the name for ionic compounds

• However, subscripts can be used to help determine the charges of these metals that have more than one positive charge (transition metals).

Other Ionic Compounds

• Not all compounds are binary.

• Baking soda has the formula NaHCO3.• Example of an ionic

compound that is not binary• Some compounds, are

composed of more than 2 elements

Naming Polyatomic Ions

• The name NEVER changes• You do not add or remove

any letters• You simply write the name

of the polyatomic

NH4ClO3 = ammonium chlorate

Example

Name of CuO Need the charge of Cu O is -2 Because 1:1 ratio, Cu must be +2 Copper (II) oxide

Example

Name CoCl3 Cl is -1, there are three of them = -3 Co must be +3 Cobalt (III) chloride

Examples

Write the names of the following Na3N CrN PbO2 K2Se

Li(CN)Fe(OH)3

(NH4)2CO3

NiPO4

Things to look for

If cations have (), the number is their charge.

If anions end in -ide they are probably off the periodic table

If anion ends in -ate or -ite it is polyatomic

Naming

1. Write the symbol of the element (or polyatomic ion) with the positive oxidation number or charge

2. Write the symbol of the element (or polyatomic ion) with the negative oxidation number

3. The charge (without the sign) of one ion becomes the subscript of the other ion.

• Reduce the subscripts to the smallest whole numbers that retain the ratio of ions.

1. Write the name of the positive ion

2. Check to see if the positive ion is capable of forming more than one oxidation number.

3. Write the root name of the negative ion. The root is the first part of the element’s name

4. Add the ending -ide to the root.

If more than 2 elements, you are dealing with a polyatomic

Writing Formulas

Recap of instructions

In-Class Assignment/Homework

Finish Criss Cross WKT from 2/27

C2O4 = Oxalate