Is that magic?

Is amazing right? But is not a magic, it is due to some chemical reaction which allows it to change colour continuously. Firstly have to special thanks to NUS High School as this experiement is learnt from them.

To do it, you need to have license to purchase the chemical and you have know how to calculate concentration of the solution. As the concentration of the solution is important to allow the reaction to happen. Lastly, I have to apologise that my video is not vertical as I do not know how to adjust the video from my blog. The video is actually showing a conical flask on a magnetic stirrer and it will continue to change colour without adding anything to it.

So to perform this "magic" you will need to prepare 3 kind of solution (solution A, B, C).

Solution A : 4M of hydrogen peroxide

Solution B : Add 21.5g potassium iodate, add approximately 400ml of distilled water and finally add 2.15ml of concentrated sulphuric acid and then top up to 500ml with distilled water. This gives you 500ml of solution with 0.2M potassium iodate in 0.077M sulphuric acid.

Solution C : Dissolve 8g of malonic acid and 1.7g of manganese (II) sulphatemonohydrate in approximately 25oml of distilled water. Add in 30ml of 0.5% soluble starch solution into the mixture. Finally top up to 500ml with distilled water. This will gives you 500ml of solution with 0.15M malonic acid and 0.02M manganese (II) sulphate.

500ml of each solution is made. However if you do not have such a big conical flask (need at least 2L conical flask). You can just take 200ml of each.

Firstly we will mix 200ml of solution A and 200ml of solution B into a big conical flask with magnetic stirrer. Keep stirring it and then pour 200ml of solution C into the mixture.

This step will start the magic, the solution will turn from colourless to amber and then blue black. The exact theory is not known. But it is may due to the hydrogen peroxide causes the iodate to become iodine so the solution turns form colourless to amble or brown. Then the iodine will react with the starch present to turn the solution to blue-black. However I am not sure why it turns colourless again, maybe the iodine will dissappear again and later come out again? Anyway this reaction do not last forever. It will remain dark blue after stirring for more than 10 min.