6.2 Names and Formulas of Common Compounds

Common Names and Chemical Names

Common names can be confusing when naming compounds

Inaccurate and provides no hint of elements present

Chalk

writing chalk (calcium sulfate)

Antacids (calcium carbonate) – also in sea shells, snail shells, eggshells

Every compound has a name and formula

Chemical formula – identifies which elements, and how much of each are in the compound

Ion Charges

Ion notation – element symbol with a superscript and a + or – sign at the top right

Some metals are able to form more than one type of ion (have more than one charge)

A Roman number is included in the ion name to show the ion charge

(I) = 1 (II) = 2 (III) = 3 (IV) = 4

Non-metals Name of non-metal changes to ‘ide’ at

the end

Naming Ionic Compounds

Rules 1) Name the metal ion first (simply the

element name). **If an element can form more than one

kind of ion, include the Roman number to indicate the charge.

2) Name the non-metal second. Change the ending to ‘ide’.

**subscripts (small #) are ignored for naming compounds

Multivalent Elements

For elements that can make more than one ion

You can find the Roman # to use by using the subscripts in the formula

This is written in the middle of the compound name

Writing Formulas for Ionic Compounds