How Chemicals "Dew It"

This is a fun reaction - it even sounds like fun when you explain the mechanics. Diphenyl oxalate is a dimer. A dimer is a molecule that is made up of two identical molecules (monomers) that are attached in mirror image - often through the use of a third molecule. If you imagine the Barbee Twins of Playboy fame sharing a double-headed "toy", you will get some idea of what this looks like. If you are like me, you will get a little something more from this vision as well (and it even gets better). The baking soda buffers the solution to a comfortable pH (like dimming the lights, I'd guess) for the reaction to proceed. When hydrogen peroxide reacts with the diphenyl oxalate dimer, it makes the dimer very unstable (like adding some tequila to the twins scene). Some dye that is in the solution gets exited; as would anyone. An exited state for a dye is as if you added energy to a garter by pulling it back. When you release the garter, there is a noticeable discharge of energy - usually a delighted squeal if timed correctly and performed with finesse. In this case, the dye releases a photon of energy as it collapses. Then everyone has a cigarette.



Here's the rub:

  1. The coloring in Mountain Dew is probably not the type of dye that can be "turned on". It is always sort of a day-glow green even without the "Chems Gone Wild" video part. It is likely a conjugated dye. These are long-chain carbohydrates that work by passing an electron from one end to the other (like one of those ball-passing relay races) at a certain frequency that determines the color that we see. If the kids can pass the ball over their heads down the line and between their legs to the front of the line at about 575 trillion times per second, then the whole line of kids would look green. Conjugated dyes don't cause as much cancer, but the metaphor to describe them isn't as much fun, either. You probably need to add some dye that is switched on by the dimer.
  2. There is no diphenyl oxalate in Mountain Dew to excite the dye. "phenyl" anything is usually not good for your diet.
  3. The hydrogen peroxide under your sink is probably not strong enough to activate the unstable dimer (like using tea instead of tequila).

You could solve all of this by adding the contents of a glow stick to the bottle. (This is probably why there is a break in the video at 29 seconds.) Don't break the glass vial of hydrogen peroxide solution inside the glow stick when adding the diphenyl oxalate and dye solution. It is about 15 times stronger than the drug store stuff you normally use, and you won't soon forget touching it. It has that same keen foaming thing as the solution that you use at home, but it soaks into the skin a little before it has a chance to really foam up. The white stains on your fingers are not bleached skin, but a look into your skin at the expanding foam that is trying to inflate you like a Times Square parade float. It stings - trust me. Also, at 30%-35% solutions, hydrogen peroxide is a very unstable chemical. It can be used to form an effective rocket fuel under highly controlled conditions, or a really big bang under the wrong conditions that tends to precipitate roofing repair contractors and mourners.

Another turd in the punchbowl,
Bob Peeples, PE