Traffic Lights - Periodic Table of Videos
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- čas přidán 21. 02. 2010
- The traffic light reaction sees a solution change colour from green to red to amber.
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There is nothing stupid about enjoying learning something new. Sadly as we get older, we tend to lose this enjoyment. I for one applaud the University of Nottingham for doing an excellent job in keeping the fascination alive.
Neil always reminds of that guy from GoT Season 1/2 without a tongue. same hairstyle, same facial expression, and they both have equal dialogue time on screen.
So true!
Ilyn Payne.....
Showed this to my science teacher a year ago, I think. And now he's using it all the time when we have chemistry.
Keep up the good work... A lot of students apreciate your help :D
what happens if we overshake it
That oxygen tank is size "W". For Wumbo.
W...wide? Wow that's big? Whoa now?
Wholly too much, With Excess, Without end. lol.
astrong0 Whopper
Patrick saying this somehow springs to mind
The size of my wiener
no explanation?
Well, science happens, which causes pretty colours. For a more detailed explanation please visit.......the Internet.
... THEE IINTEERNEEEETTTTTT!!!!!!!
Mexi Chemia There are no manganese ions in this demonstration, though. The colour results from redox reactions between the indigo carmine and glucose.
I see a lot of "the internet" comments in reply to this... This is a science channel... This is typically where the internet would lead you, so i agree, there should be an explanation
@@jhyland87 They explained it...
How about doing this with the high-speed camera? It would be interesting to watch the colour changes in slow motion - the Iodine Clock video was fascinating in slow motion.
Can you PLEASE show how it can go back to green again?
I'm quite surprised she's not wearing gloves, considering the fact that she's making a pretty strong base with the sodium hydroxide.
That is great !!
As always Thanks from Italy.
The stream of yellow liquid turning red as it hits the flask is a really neat visual effect :)
Love that demonstration, fun to watch.
Can you get it back to green?
I think the answer is no. It was green because of the temperature difference, I think. You can't revert that and cool down some molecules and some not.
Theoretically? yes
In practice? you'll have to put some effort into this
Great video! Forwarded this to my students x
Brady and the crew deliver again! This was pretty good :D.
I love this video! It looks like fun! I'm sure the children love that reaction! Your videos are awesome!
Thanks
Amazing, thanks for the great upload!
Awesome! I love the these videos as well as Sixty Symbols! Keep it up!
i love how the red-green transition is instantaneous.
Wow that's really cool! I did it with potasium permanganate intead of indigocarmine, but that ins't reversible that way. This is way more awesome!
@KlaxonCow:
Well put, VERY well put!
that is so cool, I really like the pouring of yellow and when it hits the surface it is totally red from the O2 so cool
Cool, very nice experiment.
My favourite Periodic video!!!
Good video. Would it work with sucrose instead of glucose? That is more readily available in the US.
Indeed. I did that one for my coursework; very nice.
this one accually gave me a stroke of genuine childish awe. i feel silly and privileged at the same time.
Is there a certain molarity you have to have the NaOH solution? Also does it matter how much sugar you use? (I plan on creating a design lab based off of this reaction)
pretty cool experiment!
That's so awesome!
That's quite interesting! I would appreciate if you could you chemically describe exactly the reaction. Thank you for these videos!
Could we also use an oxidation agent like H2O2 or NaOCl to reverse this reaction?
that was ridiculous! very cool reaction!
this is a really nice effect
@periodicvideos I like these videos a lot, but maybe it is a good idea to make some annotations about safety when it comes to certain materials and experiments. Untrained people might wanna copy the experiment at home without knowing the effects and reactions from the substance that is used with certain other materials.
But keep the videos coming, I learned a lot, and now I have a better understanding of the elements.
This just topped my list on the best chemical reaction!
amazing video
That was awesome!
When I first started forensic science I tried to explain this reaction to my chemistry teacher. She had no idea what I was on about and told me it must be universal indicator solution. -_-
Well, now I know.
Very good video :) thank you
Good videos. Keep them up. Do you take requests?
there's a really awesome chemical reaction where you put some chemicals in a beaker on a stirring and heating machine and it changes colour back and forth on it's own
I did enjoy it, ty sir.
What a fun experiment!
Can you please make a new video since you have got a new high speed camera and i would like to see this reaction in slow motion? And it will also be very nice if you will explain the chemistry that is taking place. Thanks
awesome experiment.
May I have the amounts please. Thanks!
Is it some sort of reversible redox reaction?
that was fantastic!
its also cool how the yellow-red change happens
That. Is. AWESOME!!!
Yes. It's quite easy to get (at least here in Austria) even by mail order. But it's not as harmless as it looks. The solution with water is caustic. Just have to know what you are doing.
Indigo Carmine is used as (blue) food coloring and glucose is (grape) sugar. NaOH is also used to prepare lye rolls (quite common here in Austria). I wouldn't drink it though. I don't know the concentration, but a NaOH solution is alkaline (this is the reason for the color change; indigo carmine is also an pH indicator) and can be caustic.
But you could dunk some dough in it, bake it and have some nice blue sweet lye roll ;-) . Just do it in a kitchen and not in a lab (no foods in a lab!).
Can someone explain why chemical reactions are able to change colors that we percieve?
Poke Playah I would assume it's probably because since the chemicals mixed in with each other, it absorbed different amounts of light, changing the visible color to us.That's just an assumption though, don't take my word for it
Poke Playah electrons play a large role in determining the chemical and physical properties of a substance.
***** Thanks man
+Poke Playah In this reaction, glucose (an aldehyde) is in an alkaline solution of Sodium Hydroxide (NaOH) and is slowly oxidized by dioxygen (O2) to form gluconic acid:CH2OH-CHOH-CHOH-CHOH-CHOH-CHO + 1/2 O2 -----------------> CH2OH-CHOH-CHOH-CHOH-CHOH-COOH
Gluconic acid is converted to sodium gluconate in the presence of sodium hydroxide. Indigo carmine speeds up this reaction by acting as an oxygen transfer agent. By oxidizing glucose, indigo carmines oxidation state is itself reduced, and becomes green. It is then reduced further and becomes red. Again it can be reduced further and will turn yellow. If there is a sufficient available oxygen (from air), indigo carmine is re-oxidized and the yellow color of solution can be restored to red. So basically what is happening is the indigo carmine is going under oxidation state changes (So called "redox reaction" for Reduction-Oxidation Reaction). But as chris handy said, it is the different molecules that are being formed and their shape that causes light to be absorbed and emitted at different frequencies (by extension, colors). Just thought it would be handy as to why the reaction actually can change several colors!
Source(s): I'm currently attempting to get my organic chemistry Bach. degree
Caleb Price TL:DR
We preform this demonstration at my school, we place the solution in a bottle with a good amount of air head space. Swirling the solution will turn it red, shaking it vigorously will turn the solution green. If anyone is interested in demonstration chemistry I would suggest checking out books by Bassam Z. Shakhashri. He has many experiments like this one with in-depth explanations of the processes involved.
superb!
Fascinating!
Brilliant!
i watched it again. its awesome.
It's works too with Potassium Permanganate (KMnO4) instead of Indigo Carmine
Sir Ryu so glucose with NaOH with potassium permanganate will work?
sry stupid ctrl+c/ctrl+v mistake you are 100% right, and it was nice of you to explain the reaction
The cylinder is SIZE W for WOAH, that's a lot of O2.
Actually, it's size W for WUMBO.
is this a redox reaction like the blue bottle reaction?
That's one big ass conical flask. Cool reaction
love this
can u buy the dye indigo carmine for demos at a store or online? and the sodium hydroxide?
I think Sodium Hydroxide is a common cleaning product,so you should be able to find it quickly
Since these are somewhat harmless chemicals you can buy them online easily.
would this work with any base and indicator? or should it be solid NaOH [we haave liquid]; we dont have indigo die either. any substitute?
What are the reactions taking place?
this was super!
That's pretty awesome.
amazing!
this is my favorite at home reaction
amazing! :)
holy hell, that impressed me. wow.
THAT IS SOO!!!! COOL!!!
what are the materials i need to do this?
Is this like an equilibrium type thing?
This still amazes me.
Anyone notice the green tint as soon as it hits the bottom of the container when she pours it, its only there briefly but try and pause it
Pretty cool!
What manner of sorcery is this?
this is cool but it's freaking lame that you don't explain anything about the chemistry
François Canguilhem they do in other videos
So could you take the oxygenated solution and apply a vacuum to turn it yellow, right?
I wonder if they'll do the Briggs-Rauscher reaction.
( T_T) Why liquids in labs always have to look like Kool-Aid?
+Noel Goetowski
No, the question is, why does Kool-aid look like luquids from a lab :o
+Johanssen Gan Because it contains chemicals OOOOoooOooo!
:o
Wash_Your_Fruits It sure worked for me! ( ×u×)
I hope there isn't a story behind this.
Isn't indigo carmine a pH indicator?
How about giving an explanation of the chemical reaction for those of us with a bit of chemistry in our background?
awesome!
@aashish7kumar5 actually if watch the entire series you will hear him speak. i can't recall which video but i have heard him speak. it is quite rare.
Those are some fancy stoplights. Where I live, we just used colored LEDs.
Very awesome :)
They should have had one of those airstones that are used in aquariums to spread the oxygen more evenly.
In fact, i wonder if there could be some cool application with just regular air making a lava lamp type of thing.
Sodium hydroxide catalyzes the glucose sugars ability to act as a reducing agent. Glucose reduces the original oxidized indigo carmine. Oxidized indigo carmine is a green colour and reduced indigo is amber orange. The red colour we see before it gets to amber is actually a transition step (like a half reduced indigo). bubbling oxygen into the mixture reverses this process re-oxidizing the indigo molecule making it red. As of why indigo is these colors at these steps, well, electronic transitions
very nice
Would it turn back to green / blue if you added hydrochloric acid ?
What would happen if you catalyzed the solution? Or just simply evaporated the water? What kind of solution would be left?
When I commented on it, it was one of those "pictures decided not to load today" pics. Haha
what concentration of glucose n sodium hydroxide are we suppose to take in the water?
It drives me bananas when you handle chemicals without gloves
Man the moment when it just became red as soon as it hit the beaker was trippy af