Mole Day — An Explanation

Happy Mole Day!

For many of you, it’s likely you have no idea what a mole is. Sure you know of a mole as a raised piece of skin that’s darker than the surrounding area. You also know a mole as a small underground-dwelling insectivore. It’s possible you even know a mole is a type of spy. There’s even the kind of mole that you put on your food, but that’s pronounced differently. “Mole-ay” sauce, as it’s pronounced, is a dark-red/brown chili-based sauce used in Mexican dishes.

But there’s also the mole used in science. A mole, whose unit is simply mol (mole : mol :: kilogram : kg :: meter : m), is a unit of measure used almost exclusively in chemistry.

A mole (mol) is an amount of substance that contains as many particles* as there are atoms in exactly 12 grams of carbon-12.

*By particles, I mean atoms in a sample (such as C) or molecules in a sample (such as H2O).

So 1 mole of carbon has the same number of “particles” as 1 mole of anything else, be it water, sodium, or gold.

Now what is that number? The short answer is, it isn’t important. lol

The slightly longer answer is 6.02 x 10^23, which is called Avogadro’s number. Yes, it’s a HUGE number.

So if you have 1 mole of Carbon (pure carbon 12), it will weigh exactly 12 grams and will have 6.02 x 10^23 number of carbon atoms in it.

If you had a mole of water, it would have the same number of H2O molecules, but would weigh 18 grams (16 grams for the oxygens and 2 x 1 grams for the hydrogens).

So just as a dozen diamonds (made of carbon) would weigh a different amount as a dozen gallons of water, so does a mol of carbon weigh a different amount than a mol of water!

If at this point, you’ve missed what mole day could be celebrating, I will tell you that today is October 23rd. Otherwise known as 10/23, a magical part of Avogadro’s number. 🙂 So scientists and numerologists unite! And at 6:02 am and pm, particularly, celebrate.

%d bloggers like this: