Rules for Naming Simple Chemical Compounds

Rules for Naming Simple Chemical Compounds

1. Names of compounds containing two elements end in –IDE. The symbol of the element that has given up its electrons (undergone oxidation) is placed first.

MgO – Magnesium oxide

2. Acids that only contain two elements are usually named HYDRO --- IC acids. Remember that all acids contain H, but all compounds containing H are not acids.

HCl – Hydrochloric Acid HI – Hydroiodic Acid

Acids with multiple elements have names you may have to memorize..

H₃PO₄ – Phosphoric Acid H₂SO₄ – Sulfuric Acid

3. Radicals are groups of atoms that stay together in many chemical reactions, and act like single atoms. These have special names.

Bicarbonate -HCO₃^- Carbonate -CO₃^-2Hydroxyl -OH ^-Nitrate -NO₃^-Phosphate -PO₄^-3Sulfate -SO₄^-2

4. When two elements form a series of compounds, the prefixes MONO-, DI-, TRI-, TETRA-, PENTA-, etc. meaning 1, 2, 3, 4, or 5 atoms of the element in combination may be used to distinguish them.

CO – Carbon Monoxide CO₂ – Carbon Dioxide SO₂ – Sulfur Dioxide SO₃ – Sulfur Trioxide SO₄ – Sulfur Tetraoxide

5. Many compounds have three elements. One of the three is usually oxygen, which is part of a radical. These substances may have names that end in –ATE or –ITE. The ending –ATE tells us that the compound contains more oxygen than a related compound that ends with –ITE.

NaNO₃ – Sodium Nitrate NaNO₂ – Sodium Nitrite

a. The prefix PER- means more of an element than is found in another compound of those same elements.

b. The prefix HYPO- means less of an element than is found in another compound of those same elements.

6. Many elements have more than one Oxidation State. Copper, iron, and tin are examples. Copper as a compound with another element can have a +1 or it can have a +2 charge. Iron can have a +2 or +3 charge.

FeCl₂ – Ferrous Chloride or Iron (II) Chloride FeCl₃ – Ferric Chloride or Iron (III) Chloride