[kazaam]

I am doing an experiment in which I have to determine the concentration of hydrogen peroxide in a variety of consumer products.

I have limited standard concentrations of Potassium Permanganate (0.02M), 20 Volumes Hydrogen Peroxide and 1M Sulphuric Acid.

I have tried many times but I can't get the reaction to work.

I'm wondering if using a heated plate will work, and what temperature is best as I think the decomposition rate of H202 rapidly increases with temperature. I have been told 20 volumes H202 is approximately equivalent to 1.76M, is this correct?

For the pilot experiment to get my method right:

I diluted the concentration of the H202 by a factor of 10 by using a pipette, taking 5ml, putting this into a 500ml standard flask and adding deionised water up to the mark. Then I poured permanganate solution into the burette and titrated adding 1M sulphuric acid at the start into the conical flask with the diluted H2020.

But its not working! And I am really stuck.

I'd really appreciate any *delete me*

[Borek]

What is happening when you start titration?

http://www.titrations.info/permanganate-titration-hydrogen-peroxide

[kazaam]

thanks for the link and reply
Pretty much nothing happens to be honest! the H202 stays clear as I keep adding the permanganate and I don't know how much H2SO4 to add and whether the number of moles of sulphuric acid makes a difference.

I really massively appreciate your help by the way! That link u gave me is fantastic. I will definitely use it tomorrow and just noticed it includes ratio of sulphuric acid to add!

Cheers. But I'd still appreciate advice about heating.

[Borek]

If it stays clear it means permanganate is still getting reduced, so whatever you are titrating is still there. Also, if it stays clear, there is probably enough sulfuric acid, at least at beginning. Amount of acid should not be important - all you need is to be sure it is in huge excess and pH of solution is low. You can easily calculate how much acid can be consumed by the permanganate reaction - you know amount of permanganate in burette, you can't add more than you have.

Try to start with smaller volume of hydrogen peroxide, or dilute it not 10 times, but 50 or even 100 times before titration. This way you will need smaller amount of permanganate and you can be able to at least estimate how much titrant can be needed. Alternatively, add whole burette of titrant - if the solution is still clear, there was not enough permanganate, if it is pink - well, you know endpoint is somewhere in between.