How does THAT work? Why Essential Oil and Baking Soda Freshens the Air

When I spoke of chemicals the other day, it got me to thinking....what if I tackle a question every so often that everyone is wondering, but not many people know the answer?
I'm not saying that I know everything. FAR from it. What I am saying is, I have a lot of smart friends. Like neurobiologist, lawyer, chemist type people. If I cannot figure out the answer, one of them usually knows. And trust me, I go to them a lot. Like, a lot, a lot.

And yesterday the question popped into my head--if baking soda is used as an odor absorber, how can people add essential oil to it and call it an air freshener? Wouldn't it absorb the smell of the oils, too, and NOT freshen the air?

So I went to my handy dandy chemist friend...and here's the answer....


Polarity.

Yup. You heard it here first. Polarity is the answer.

Oh, you don't know what that means......me either. I mean, I know what polarity means (ions of a thing are either positive, negative, etc)..think of a magnet. One side is polar, one side is non-polar. Or, the two sides (things) are opposites.  Positive negative, yes no. Whatever you want to call it.

Baking soda is polar. Water is polar, and as a general rule (if there is such a thing), if something dissolves in water, it is polar (like dissolves like).

And as you know, essential oil is an oil, and doesn't dissolve in water, so it is non-polar.
The essential oil will mix with the baking soda, sitting on the surface of the baking soda particles and not dissolve, and thus release its fragrance.

When you add essential oil to baking soda, you are spreading out the oil over the surface of the baking soda, and since the two are polar opposites, they do not dissolve/mix...they kind of join in a handshake that never lets go.

Huh. That's good to know.