Hi Theopoline Itenge, according to the "cross over rule" you need to mix 0.125 mL of the 40% hydrogen peroxide with 39.875 mL water to obtain a 0.125 % solution. This means that for 1000 mL you should take (rounded) 3.1 mL of the 40% solution and mix it with 996.9 mL of water.

Please look at the following below links which may help you in your analysis:

http://idealcosmeticos.com.br/en/produtos/view/agua-oxigenada-cremosa-40-volumes.html

https://shop.matuskataxidermy.com/products/hydrogenperoxide-40volume

Thanks

The volume here is used to define the the amount of oxygen present in/released by the peroxide. The 40 volume here means every 1 cubic cm of this Hydrogen Peroxide will produce 40 cubic cm of Oxygen.

Never heard of "40 volume" hydrogen peroxide, but found out it does not mean 40% but 12%. So, use 3.3 times as much H2O2 as Frank Edelmann calculated.

Dear Theopoline Itenge, you should check carefully what the label on your bottle with H2O2 tells. I agree with Willem H Koppenol in that nowadays only 12% hydrogen peroxide solutions are freely available. However, 30% solutions used to be quite common, and I clearly remember that we even had a bottle with 50% H2O2 in our lab. In higher concentrations, hydrogen peroxide can be dangerously explosive.

I agree with Willem H Koppenol , a 40 volume Hydrogen peroxide is 12%.

40 volume means that it generates 40 mL oxygen gas per mL H2O2 solution.

Calculations would be>

Take it to Liters> 40 L,

mols? =(approx) = 40 L / 22.4L/mol (Molar volume) = 1.79 mol

==> remember 2 H2O2 --> 1 O2 + 2 H2O;

it came from 1 L H2O2,

==> initial Concentration of H2O2 = 3.6 Molar.

now use molecular mass of H2O2 (MM= 34 g/mol)

C(g/L) = 3.6 M * 34 g/mol = 122.4 g / L

C (g / 100 mL ) = C (%) = 12.2 %

Excellent that Matias Moller checked the concentration and grateful to Dipak Shilkar for alerting me that there was yet another way to indicate concentrations of hydrogen peroxide.

Back to the question of Theopoline Itenge, namely making hand sanitizer according to the WHO protocol (see attached pdf). Please note that H2O2 is only added to kill viruses or bacteria that may have been present in the 2-propanol, glycerol, or water used to make the hand sanitizer. After a while, the H2O2 will have reacted with something and will no longer be present. But the solution will then be sterile. H2O2 plays no role in killing the corona virus on your hands, that is done by the 2-propanol, or by the ethanol. We have made it for our neighbours and for the people in the grocery stores in our village.

Good luck Theopoline!

Hi Theopoline Itenge, 40 Volume or V40 Hydrogen Peroxide does contain 12% H2O2. Thus my initial calculation should indeed be modified as suggested. I was assuming a content of 40 vol.% H2O2 per liter which is a pretty high concentration that you can't buy at the pharmacy.

I also did not hear about 40 Volume H2O2. However, based on the description on the internet of making home-made skin creams for bleaching and/or exfoliation, I guess it is 40% (V/V) of 3% H2O2 (3% H2O2 is available in drug and food stores). The final concentration of H2O2 in the final product would be 1.2%. I think 12% H2O2, suggested by some scientists, is too dangerous for any skin-care applications.

Thank you Rao for the answer.

I went to a local Pharmacy, and it was confirmed that 40 Volume H2O2 is equivalent to 12% V/V. Since WHO formulae uses 3% V/V, I only used 1/4 of the amount recommended in the WHO recipe.

In other words, for a total volume of 1000 mL, amounts are as follows;

96% v/v ethanol = 833.3 ml

12% v/v H2O2 or 40 Volume H2O2 = 10.425 ml

*98% glycerol = 14.5 ml

Distilled water = 110.5 ml

The recommended final concentration of H2O2 is 0.125%

I am grateful to all the answers forwarded.

I fully agree with Theopoline Itenge in that "40 Volume H2O2" means a 12% v/v aqueous solution of hydrogen peroxide. A problem with this specification is that it is not used in chemistry but in hairdressing /hairstyling (see attached pictures). 40 Volume is the highest concentration using for hair bleaching. The second picture comes from a book entitled "Science for Hairdressing Students" and explains the situation in detail.

The Pharmacy had these concentrations; 10V, 20V, 30V and 40V.

What I did not understand is that all the 4 different concentrations were priced the same. One would think that the highly concentration bottle would cost less, since you would use less volume. I bought the 40V bottle thinking I was going to get more "value for money"!

I have also learnt that higher concentrations is not always equal to "value for money", so to speak. Not in the case of H2O2.

Why? because as pointed out by Frank, in higher concentrations, hydrogen peroxide can be dangerously explosive. One would be better off to just buy the 10V I suppose and just use the 41.7 mL as indicated in the WHO protocol.

I meant, the high concentration bottle would cost MORE, since you would use less volume.......

A correction to statements by Theopolinge Itenge and Frank Edelman: A concentrated solution of hydrogen peroxide in water, liquid or frozen, is not explosive by itself. It requires initiation by another explosive. When the H2O2 vapour concentration exceeds 26 mol% (75% by weight H2O2, boiling, T = 128°C, atmospheric pressure) an explosion can occur, see W. C. Schumb, C. N. Satterfield, and R. L. Wentworth, Hydrogen Peroxide, ACS Monograph Series, New York, Reinhold, 1955, p. 181 (unfortunately, this book is not widely available). In practice, that means that when you distill off water from a H2O2-H2O mixture, you do so under reduced pressure. You can get to about 90% H2O2 that way.

Dear Theopoline Itenge, don't worry about the concentrations which are available at your pharmacy (10V, 20V, 30V and 40V). They are all considered rather dilute, and they present is no risk of explosion. For more information, please check out the attached safety advice issued by USP Technologies, a manufacturer of H2O2.

agree with Frank T. Edelmann , thanks for your valuable answers

The volume here is used to define the the amount of oxygen present in/released by the peroxide. The 40 volume here means every 1 cubic cm of this Hydrogen Peroxide will produce 40 cubic cm of Oxygen.

40 Volume hydrogen peroxide mean 12% of hydrogen peroxide.

Volume is the amount of oxygen that is contained in a given amount of peroxide. For example, 3% hydrogen peroxide is V10 or 10 volume, because it will release 10 times it’s volume in oxygen. One pint of 3% hydrogen peroxide will release 10 pints of oxygen as it breaks down.

If you want to use 3% of hydrogen peroxide, then dilute it or take 1/4th of required concentration.