Recreating the chemical traffic light reaction

Note: I made a mistake in the video. I said the carbonate solution would have a pH around 8-9, but it would actually be closer to 11-12. I was thinking of sodium bicarbonate when I said that!

my chemical trafficlight is my favorite band

It continues to surprise and upset me how hard it is to find information about these kinds of things. Science being the published and reproducible knowledge of humanity, you'd expect that a smart chemist with internet access would find it easy to get all the information they need to reproduce these reactions. Yet there's so much that isn't known, or isn't published, or isn't freely accessible. We've got a lot more work to do.

Keep up the amazing work! We love your stuff! Chris from HTME!

Nice, That almost went turquoise. I do like that one better.

I'm too stupid to fully comprehend this but I watch it for fun.

I think it'd be really interesting to see what colour changes happen when you bubble oxygen through either of these solutions

I do this live in my Science Shows (at schools, academies, libraries, museums, etc) many dozens of times a year. It’s a touchy reaction but as long as the ratios are right and the water temp is just “warm”, it’s pretty foolproof. I actually use ordinary tap water (Hill Country TX hard water) and it works well. I’ve pushed the reaction to its comfortable limits, mostly out of laziness. My reactions are: 400 ml of warm (~100°F) water (I eyeball it), 10.5-11g (dry weight) Sodium Hydroxide, and 2 tsps finely powdered corn sugar (brewing supply). I mix the water, base and sugar in a flat bottom round flask by shaking and venting. Then add the Indigo Carmine. As long as the water temp is just warm when you start, the reaction is fast enough for live stage demos. And a little traffic humor doesn’t hurt. I’ve even performed this reaction on live TV (an NBC affiliate morning show), although the green screen equipment inadvertently chroma-keyed out my “green” and replaced it with an eyeball hurting white, which I didn’t know until after the show had aired, Lol! Love your channel! TV demo: https://www.kcentv.com/mobile/video/life/daniel-g-benes/500-8192922

A good example of a classic school chemistry trick. Looks lovely and younger audience is always impressed. It also shows how beautiful chemistry is!

That was so neat; definitely loved the second color changes more as well. The subtle gradient was awesome

This is phenomenal as always. I really hope that at some point in your life you become a chemistry teacher, I really think you’d be able to make a “boring” subject interesting for regular people (i.e. students) and that you’d make people feel actually engaged and fascinated by science while they’re learning. Please keep these up, you’re doing incredible work.

Completely agree that your version is visually more interesting! I really like when you add those little extras in to show some out of the box thinking.

Yeah, I definitely like the Carbonate solution version better than the NaOH. The better range of colors is much more appealing, despite it not having as prominent shifts in color. Channels like yours with experiments like these reinforce my choice to be a Chem major, and I’m excited to discover the world of reactions and applications out there. Thanks for the inspiration!

Every day i look to see if you have another video and today i was happily suprised! thank for making the best chem vids out there!

Finally, I've been waiting for the next video. Great content, keep it up.

I love this reaction and I demonstrate it to my students on a regular basis. They love it and think it's like magic! It's similar to the Blue Bottle experiment using methylene blue but better. Thanks for posting.

Nile, i've been watching you since your fuming nitric acid video 4 years ago and i gotta say, your video just get better and better, you never put out bad content, thanks for all the work you do to keep us entertained and for teaching us so so many cool new things, have a wonderful christmas bro <3

Missed school today, i guess this will take place of my ap chem class for today

Chemistry was my first great love, ever since my parent gave me a chemistry set at age 12 and I found some home experimenting books from the 1950s in the public library and a friendly pharmacist willing to help out and sell me modest amounts of chemicals (including the fun stuff, oxidisers and dilute acids, the only thing he refused to sell me was concentrated H2SO4) I still feel like that same curious kid watching vids like this. Love what you do, keep it up.

I love your videos @NileRed, they are so informative and interesting. You should make one completely about chemical elements.