Email Jean Hein for handout, is, like, 95% petroleum distillates, which sounds a lot like hexane. I’ve lost the reference, but I made a nice handout. This was all very exciting - a beautiful, practical, engaging kick-off to a larger lesson on intermolecular forces. The ink can be friction-removed wiping with a wet paper towel also works, but not because of the water. But when another marker-tip was stirred in hexane, the dye dissolved - evidence that the ink from a dry-erase marker is non-polar. I stirred a dry erase marker-tip in a beaker of water no ink dissolved. Next question: is the dry-erase marker polar or non-polar?Įvidence suggested that is non-polar, but how could we verify? Another student added that if one writes overtop of Sharpie-ink with a dry-erase marker it will be erasable as usual, which totally worked. It didn’t take long for someone to suggest hexane as a solvent to remove the Sharpie-ink, which it did beautifully. So the question was - is the Sharpie-ink polar or non-polar? Right: Iodine dissolved in hexane layer atop an aqueous layer. 1 Left: Hexane layer atop an aqueous layer with KMnO 4. There were gasps they knew the board eraser wouldn’t rub that ink off.įig. On a whim, I took a Sharpie 3 and wrote on the white board. We talked about “Goo-Gone”, a non-polar solvent, 2 and how it can be used to remove the gunk that remains when a price sticker is removed.

This led to a fruitful discussion about density, solubility and a bunch of things I can’t remember. With a bit of showmanship, it appeared as if the purple layer moved from top to bottom (or vice-versa). I began with a side-by-side demonstration: one separatory funnel contained hexane (clear) atop KMnO 4(aq) (purple) the other had I 2 dissolved in hexane (purple) atop pure water - see Fig. The topic was an introduction to solubility - “like dissolves like”. I just had the most wonderful Grade 11 Chemistry lesson that really took off in the final few minutes. Dry-erase markers - and the teachable moment

Erase marker