Oxidation numbers are the "effective charge" a particle has in a molecule or ion. While all atoms WANT to have a full outer shell, and they TRY to lose or gain electrons, they sometimes aren't able to. We all know that you don't always get what you want. Sometimes 2 non-metals are forces to share electrons. Both WANT to gain electrons, but the more electronegative element will get the electrons most of the time. In other words, they don't share equally. Oxidation numbers tell us what the charge really is in a particle situation. Manganese can form a +2, +4, +5 and even +7 charge depending on what other atoms are around to take its electrons. While sulfur wants to gain 2 electrons and form a -2 charge, it is very common for oxygen to grab its electrons and sulfur is left with a +6 charge. It now has a full outer shell because its lost ALL its valence electrons.
Follow these rules to determine the oxidation number of an ion-
You can calculate the charge of an ion by using the entire compound (must =0) or a polyatomic ion (must = the charge given). Here are 2 ways to calculate the charge of sulfur in sulfuric acid.
No matter which method you use, the oxidation number of sulfur in sulfuric acid is +6.
No comments:
Post a Comment