Covalent Compounds
Molecular compounds are compounds that bond two non-metals by sharing electrons. Examples of molecular compounds include carbon dioxide, hydrogen peroxide, and sucrose. To name a molecular formula, prefixes are used for both elements. The prefixes are mono- (1), di- (2), tri- (3), tetra- (4), penta- (5), hexa- (6), hecta- (7), octa- (8), nona- (9), and deca- (10). If there is only one ion of the first element, then mono- is not added. Like binary ionic compounds, the ending of the second element is changed to –ide, but you would also add the prefix.
For example, you are given the formula N2O4. There are two nitrogen ions, so it is dinitrogen. There are four oxygen ions, so it would be tetroxide. The whole name would be dinitrogen tetroxide.
An important thing to note is that when the second non-metal is oxygen and the prefix ends with an a, leave out the a in the prefix. An example of this is the compound above: dinitrogen tetroxide.
An important thing to note is that when the second non-metal is oxygen and the prefix ends with an a, leave out the a in the prefix. An example of this is the compound above: dinitrogen tetroxide.
A quiz to practice naming covalent compounds: http://chemistry.about.com/od/testsquizzes/l/blcovalentquiz.htm
Model of dinitrogen tetroxide