The Chemical Chameleon

Posted by on February 23, 2011

One of the demonstrations we do in our show is the classic chemistry experiment called the Chemical Chameleon. This is a color changing reaction that proceeds on its own through a number of different beautiful colors, and involves some really interesting chemistry.

The demonstration is done by preparing two solutions.

Solution A:
About 2mg potassium permanganate (chemical symbol: KMnO4) is dissolved in 50mL of distilled water. We only need a tiny amount of this, because it creates a very intense purple color in solution and can be too dark to see if too much is used.
Solution B:
6g of sugar (C6H12O6) and 10g of sodium hydroxide (NaOH, also known as Lye) is dissolved in about 750mL of distilled water.

Note: It’s always important to use distilled water in any chemistry experiment, because we want to make sure to avoid any sources of contamination. Tap water has lots of other things in it that are good for you, but might be bad for a chemical reaction.

Simply pouring solution A into solution B gets things going! For best results, we swirl the flask to get everything well mixed. Immediately, the deep purple color of solution A changes to blue, and very quickly after that turns green. Then, much more slowly, over a few minutes, the green fades into a yellow-orange. This is actually caused by tiny solid particles of a new chemical, manganese dioxide (MnO2) that’s been formed during the reaction. If allowed to sit long enough, these will settle to the bottom and the color of the liquid will turn clear again!

Here’s a video of the experiment in action!

If you can see this, then you might need a Flash Player upgrade or you need to install Flash Player if it's missing. Get Flash Player from Adobe.

(Note: This is test footage that will be replaced with a nicer demo soon.)

The Science:

Even though this experiment is easy to perform, there’s actually some really complicated and interesting chemistry going on! It involves something called a redox reaction. This basically means that new compounds are formed when one chemical takes electrons from another chemical. Here, the potassium permanganate is reduced, meaning it gains electrons, and the sugar is oxidized, meaning it loses some.

This happens in two steps. In the first step, the permanganate ion (the part of the potassium permanganate that changes) is reduced to the manganate ion:

MnO4- + e- → MnO4-2

The compound on the left is purple, and the one on the right is green. As this reaction is going, there is some purple and some green in the solution and these combine to make it look blue at the beginning.

Next,  the green manganate is reduced again into manganese dioxide:

MnO4-2 + 2H2O + 2e- → MnO2 + 4OH-

The manganese dioxide is a brown solid, but it’s in such tiny particles that it appears to make the liquid turn yellow.

So, that’s how you make colors with chemistry!



I’ve gotten several requests in the comments to talk about disposal, so I thought I’d mention it here. Proper disposal is an extremely important part of any chemistry experiment, to keep yourself and others safe and to protect the environment. In this experiment, the sugar is reduced to a different type of sugar (which is nonhazardous), and the potassium permanganate becomes manganese dioxide (MnO2, which is also harmless). The only thing we need to worry about is the NaOH, and this is easily neutralized by the addition of some acid until a pH of 7 is reached. I usually use 9.5M hydrochloric acid (standard concentration of hardware-store grade acid), which means we need about 26mL of acid to fully neutralize the solution. The resulting solution of sugary, salty water is then perfectly safe to pour down the drain.


71 Responses to The Chemical Chameleon

  1. Bill Science

    Wow Dan, That’s kinda cool! Not as cool as some of the stuff I do, but still pretty cool. :P

  2. Jane

    Where can you buy distilled water?

  3. Dan Science

    It’s available at any grocery store or Wal Mart in your area, in 1 gallon jugs. Make sure it says distilled and not “drinking” or “spring” water – not all water is the same!

  4. Gerardo

    Can you explain further the selection of the masses of the permanganate, sugar and NaOH? Does it has to have a certain concentration? I’m trying to vary the time of reaction by manipulating the concentration of either the permanganate or the NaOH,


    • Dan Science

      Hey Gerardo,

      I determined the masses mostly through experimentation myself, to see what ratios produced the best demo. Concentration of any particular reactant isn’t critical, it will just affect the speed of the reaction as you suggested. The reaction only happens in an alkaline environment, so changing the NaOH concentration should definitely have an effect. On the other hand, if you use too much permanganate I’ve found the colors get too dark to see very well, so be careful to not add too much! That sounds like a very interesting experiment! Have fun with your tests, and always remember to be safe when working with chemicals (goggles and gloves especially – NaOH in the eyes is extremely nasty). Thanks for the comment, and good luck!
      ~Dan Science

  5. Lee

    I have to do a project on the element potassium and this seems like a really exciting experiment to try. It’s just that the NaOH seems to be super corrosive and maybe too dangerous to take to school. (My teacher is very sensitive about safety.) Would there be a way to achieve a similar color transformation by using a safer substance? Do you know any safer experiments involving potassium that will be okay to try in a classroom setting?
    Thank you for your help :)

    • Dan Science

      Hey Lee,
      You’re right about NaOH, and potassium permanganate is pretty nasty stuff too! It’s a strong oxidizer so it will react very strongly with a lot of things, which is bad news if you aren’t careful.
      That’s a good question about potassium, and I’ve had to spend a few days thinking about it! The trouble is that, in most experiments, the potassium doesn’t play much of a role. In the chemical chameleon, it is the permanganate ion that changes and the potassium is just there to balance the charge. Sodium permanganate would work just the same. The only thing I can think of where potassium itself has an effect is in a flame test – you dissolve a potassium salt (KCl, KOH, etc.) in methanol and ignite it, and you get a beautiful purple flame characteristic of potassium. Of course, since this involves open flames I bet your teacher wouldn’t like that very much either!
      A safer demo would be to make a solution of potassium iodide and add acid to it to precipitate elemental iodine. This is neat because it makes an actual element, but again the potassium doesn’t do much in the reaction. Good luck with your project!

  6. Rose

    I am doing this experiment in my science class and I was just wondering what exactly is the chemical equation?

    • Dan Science

      Sorry for the slow reply on this! We’ve been very busy lately with our regular jobs plus Science Brothers events! I’m glad you get to do things like this in your classroom. I’ve searched and searched for an answer to your question, and the short answer is: I’m not sure! I have not been able to find much information on the web about this reaction, and I don’t know much about organic chemistry (the part of chemistry that deals with carbon compounds, like the sugar in this one). Here is what I think might be happening:

      4 KMnO4 + 3 C6H12O6 == 4 MnO2 + 6 C3H4O3 + 4 KOH + 4 H2O

      The carbon compound on the left is glucose (sugar, C6H12O6) and the one on the right is pyruvic acid (C3H4O3). It took quite a bit of hunting and a lot of thought to puzzle that one out, but check with your teacher and see if that makes sense to them too. If you find anything else out, let me know!

  7. pradeep

    thanks for uploading such a informative page which can help us in labs .
    my question ?
    why does orange colour appear during this reaction ?

  8. Soham

    The experiment is good, but I am actually trying to perform it in front of children of 7th grade. pls make the explaination of this reaction a bit simpler to understand by the 7th graders.

  9. Yash Jain

    Hello Dan & Bill I just wanted to ask weather I can join your group….pls…..

  10. Priyadarsanan

    Your web page takes my memory back to the good old school days when, as a curious student, my chemistry teacher kindled my interest in it by spectacular demonstrations of chemical reactions. Years have rolled by, my hair has now shades of grey, but chemistry has still not lost its charm on me.
    As a professional metallurgist, I find this web page very informative and makes me feel like at home like the schoolboy that I was.

    • Dan Science

      That’s great! I’m glad you enjoyed the page. You should check out my YouTube channel, mrhomescientist, for more cool experiments I’ve done! It’s more advanced stuff than what we show to the kids, but I think you’ll find it interesting. What sort of metallurgy do you do?

      Sorry this reply was so slow, your comment must have gotten lost in my inbox!

  11. Christina

    Why does the color change
    in the video:?

  12. leila

    can you explain the reaction involve in each color change? thank you.

  13. Arindam Ghosh

    Hello, I’m a student of chemistry & I have a question about the above reaction. Potassium permanganate is much stronger oxidising agent in acidic medium than in alkaline medium, why the above reaction does not occur in acidic medium? Why only alkaline medium is required?

    • Dan Science

      That’s an excellent question! Information on why this reaction works is very hard to find, and there’s not much out there. My first thought is that if an acid environment is used, the reaction may speed up (since as you say, it’s a better oxidizer). So, if you use acid instead of base the color changes may happen too quickly to catch. I’ll have to test this out, see what it does, and let you know. Great comment!

  14. Bob

    Christina and Leila, the reactions are explained above you have to read using your eyes.

  15. Bob MacAdoo

    Hello Dan Science I am a high school student and I would like to know can you give me a breif explanation of the chemistry behind the reduction of permanganate and why this happens thank you!!

    • Dan Science

      I describe what happens in “The Science” section at the bottom of the post. If you have any specific questions, let us know!

  16. jahdae

    good morning, I am a student in somersfield academy Bermuda, I am performing this experiment and i would like to know what happens in the discolouration of the solution if the concentration is increased. when more sugar is added to the potassium permanganate, does the discolouration happen faster or slower?

    kind reguards,

    • Dan Science


      Great question, and good to see others are trying out these experiments too! In my own tests, I found that what really affected the speed of the color changes was the concentration of the base (sodium hydroxide). Having a higher concentration of hydroxide greatly speeds up the changes, and it’s actually easy to make it so fast that you miss the initial blue color. I don’t think adding more sugar would have a visible effect, but that sounds like something interesting for you to try out!

  17. Dennis B.

    2 KMnO4(aq) + 2 NaOH(aq) + 2 C6H12O6(aq) = 2 C6H11O7Na(aq) + K2MnO4(aq) + MnO2(aq) + 2 H2O(l)

    Trust me, it took me a lot of hunting to find this equation, but there it is. Also, it is classified as a redox reaction, the colour change is simply the different rates of redox between the ions. Just as a side note, you were correct, having a higher concentration of NaOH does increase the speed of which the colour changes from pink to green, because it can oxidize quicker.

    I’m doing a project on this right now, just figured I’d help out others from here on in.
    Hope this helps,

  18. Dennis B.

    P.S. I did the experiment substituting NaOH with HCl, and I got a null result (the solution stayed pink). Maybe H2SO4 would work better, but as far as I know, an acidic environment as opposed to a basic one kills this experiment.

  19. Dennis B.

    P.P.S. I used 8 mL of 0.8% w/v glucose solution, and anywhere from 2.5-10 mL of 0.33 mol/L NaOH solution with 8 mL of 0.004% w/v KMnO4, and it worked really well for anyone else trying to duplicate it.

  20. Neil C.

    Hey this is great work, but I have one question. I believe there are two redox reactions taking place in the overall reaction, obviously, causing the color changes.

    If the first redox reaction is
    reduction:MnO4- + e- –> MnO4^2-
    oxidation:C6H12O6 –> C6H12O6^+ + e-

    then what is the oxidation reaction in the second redox reaction?
    reduction: MnO4-2 + 2H2O + 2e- → MnO2 + 4OH-
    Oxidation: ???

  21. oshin

    hi…. i just watched up the video and well its awesome…. and so i decided to show this experiment in my class and my class loved it…. thanks to you guys! ;)

  22. sadia

    hello i am in class i like pistachios

  23. Nemeleu

    Is there a way to control the change in color in time?

    • Dan Science

      Yes! The pH seems to have the greatest effect on how quickly the colors change. Adding more NaOH (increasing pH) makes the reaction speed up, and using less makes the changes slower. Heating (or cooling) the solutions should speed up (or slow down) the reaction too, though I haven’t tried this myself.

  24. IES Students

    We are using this experiment for a project in school. How does the molecules change in this process?
    Nice experiment by the way.

  25. Mirelle S

    You Sirs are amazing! Great way to make young people, like me, get interested in Science. (Yeah i´m a bit of a nerd)

  26. Sheccid Mtz

    Hola, soy de mexico, mi especialidad realiza cada año una expo quimica y quiero hacer esta reaccion oscilante, podrias decirme como expondrias esto en una escuela media superior?
    Porfavor contesta lo mas antes posible, debo entregar la informacion a mi maestro el miercoles, gracias por tu atencion.

  27. Sheccid Mtz

    Hi, I’m from mexico, my specialty makes a chemical expo every year and want to make this oscillating reaction, could you tell me how this expose yourself in an upper middle school?
    Please answer as soon as possible, I must give the information to my teacher on Wednesday, thanks for your attention.

  28. farahmelhem

    can u please tell me what are chemicals and materials used? and if there is a qualitative data?

  29. HK

    Hi, what is the rate law equation for this reaction?

  30. James

    I tries this in school. Use less amount of sugar(or any other similar carbohydrate, i used dextrose), and much more amount of NaOH. And use only distilled water. I used 100 ml KMnO4 dil. soln and 15-20ml of (NaOH+Dextrose+H2O). It gave sufficient color change Pink-blue-green-yellow-chrome.

  31. Allie S

    Hello thank you for the useful info.

    I have a question that i’m not really sure about.
    Sometimes the purple color goes colorless, does that mean it is reduced?

  32. Veronica Murillo

    where do you get all these ingridients

  33. rania

    Hey i have done this experiment at school and my teacher asked me a question that i couldn’t answer him.the question was:
    What happens when KMnO4 reacts with C6H12O6 except color changing? Thank you :)

  34. Peter


    I was wondering what the concentration of your KMnO4 solution was?


  35. Naksh

    Nice experiment but idid not understand how to do can u explain how to do please Iam doing an experiment in school

  36. Melissa

    Hey Dan,
    I’m a bit confused with the overall equation you’ve supposed as you haven’t included the NaOH? Sorry, I’m just bit lost. Cool experiment though!

  37. Ichinose

    This is such an awesome experiment!!! Thank you. Im doing this for my science fair!!!
    Is there any way of making this redox reaction reversible too by making the forward and backward reactions come at an equilibrium? If so could you let me know what masses of the reactants i should use? Thank you.

    • Dan Science

      Great! Have fun and be safe when handling the chemicals, potassium permanganate in particular. I don’t think there is any way to make it reversible; turning the end product (manganese dioxide) into the starting reagent (potassium permanganate) is very difficult. If you want an oscillating color change reaction, check out the Briggs-Rauscher iodine oscillator! I’ve done that one a few times and it’s very impressive (but takes a lot of chemicals)!

  38. Tera

    I want to complete this experiment, but I was sent 0.2N NaOH solution instead of the solid. Can I still use this? How much should I use if I am following your protocol? Thanks so much.

  39. Lisanne

    Hello, I would like to ask a question. I was told that the chemical chameleon a type of clock reaction is. Could you explain why this is a clock reaction?

  40. Wahaaj

    I have a few questions for you first of all I am a student from grade 8 trying to look for a science fair project idea I just want to know the level of this project and can tell me some questions for my science fair based on this project so I can observe it can you please reply within a 2 weeks or so thanks and an even answer the questions you gave me so it can be more easier thanks

  41. Bibi

    what colour change does take place when rhubarb poisonous acid react with potassium permanganate

  42. Alexandra Arenas

    I have a question, how is the waste? I need to know it, it’s so important in practice.

  43. Alexandra Arenas

    Hey, I have a question … how waste treatment done? I need to know, it is a very important part of the practice.

    • Dan Science

      That’s very true. The solution needs to be neutralized with acid to a pH ~7 before disposal. You can use pH indicators, or stoichiometry to calculate how much you’ll need. After that, the products are perfectly safe to pour down the drain.

  44. sowjanya

    hi your experiments are interesting.i would like to ask you in general one question.did you done any experiments on HCL solution because i have done one experiment which i used is 1Normality HCl for hcl recovery using membrane technology suddenly i observed color change light green after 12 hrs so if you guys know the reason why HCL colorless to light green color reason please email me it will help me in my further experimental studies.

    Thanking you.

  45. Madhav Ghimire

    How can you extract MnO2 from the solution ?

    • Dan Science

      The MnO2 is actually a solid that settles out of the solution after several hours. Then you can just filter it off and recover it.

  46. Juana

    This is such a cool experiment!!! Thank you so much!! I was thinking about doing this as a sort of “magic” trick for the kids at a camp I lead; they’re going to get a kick out of it. I was just wondering, though, what is the best way to dispose of the products when I’m all done? Is it safe to just poor everything down the sink or should I put it in a waste beaker? Thank you again for all of your help, you have been so helpful with this whole web page. Keep up the amazing work!

    • Dan Science

      Thank you! The products need to be neutralized with acid to a pH ~7 before disposal. You can use pH indicators, or stoichiometry to calculate how much you’ll need. After that, the products are perfectly safe to pour down the drain.

  47. Althea Mangasar

    For solution B is there any difference if heat was applied to it, or any scientific explanation behind it?

    • Dan Science

      Sure! Heat speeds up chemical reactions, so it should make the color changes happen faster.

  48. Jamie

    Hi. I would like to ask if the above reaction will occur if NaOH is replaced by H2SO4? Besides, what is the equation and rate law of this reaction? Thank you very much for your help!!! Thanks a lot!!!!

    • Dan Science

      Well H2SO4 is an acid, so it wouldn’t really work in place of a base. Dennis B.’s comments above have good info on the equation and experimental results. I’m not sure how to calculate the rate law, honestly.

  49. Naomie

    What kind of question should be ask when we are doing this experiment

  50. Naomi

    What happens to the Sodium hydroxide during the reaction and what is its purpose in this experiment?

    • Dan Science

      The reaction happens faster the more basic the solution is. I’m actually not sure if it participates in the reaction or is just a catalyst of sorts. Something to research!

  51. shafiq

    why the kmno4 turn to brown colour

  52. Trony

    To this project what could be hypothesis?

  53. sara patinson

    Why this solution is heated

  54. Meghan O`Donnell

    Hiiiiiiii Im over heeeeere.
    You helped me a lot in my job, thank you science brothers.

  55. Paula Urrego

    Hello, I would like to use this experiment for my science fair.I´ve seen this experiment using a magnetic stirrer , what is the difference?. Is it necessary?. Greetings form Colombia

    • Dan Science

      Hello! A magnetic stirrer would work fine, and would make the color changes happen a bit faster and more evenly. But it’s not required!

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