What is the chemical formula for sodium sulfite?

1 Answer
Sep 6, 2017

You should know what a sodium ion looks like: #Na^+#

Now the crux of the problem is that mystery... sulfite.

A sulfate ion is #SO_4^(2-)#, but we want -ite. This suffix generally means one less oxygen atom in that specific oxyanion. The sulfite ion is #SO_3^(color(white)x2-)#.

Ionic compounds are neutral; that is, they have a net charge of #0#. We need #2# #Na^+# ions to neutralize the charge of #SO_3^(color(white)x2-)#. So moving forward with this knowledge, the formula for the ionic compound is...

#Na_2SO_3#