Diluting Concentration of Hydrogen Peroxide (Food Grade):
Firstly, let us try understand various ways in which concentration of substance/s are presented. The various ways to express concentrations are:
- % w/w (Percentage Weight per Weight): While preparing w/w solutions, weight of each constituent (Chemical) is used. Let us say a 100 Grams of Solution C is made by adding 10 Grams of Chemical A (Solute) to 90 Grams of Chemical B (Solvent). Now, this gives 10% w/w Solution of Chemical A.
- % w/v (Percentage Weight per Volume): Now, we use w/v calculations when a Solid Solute is dissolved into The Liquid Solvent. Now, assuming NaCl would completely dissolve into – within the molecules of Water, so, if I dissolve 10 Grams NaCl into 100 mL of water, I have 10% w/v solution of NaCl.
- % v/v (Percentage Volume per Volume): Now, Mostly this measurement is used, when both ‘The Solute’ and ‘The Solvent’ are Liquids. Let us say,
- I add 30 mL of H2SO4 into 70 mL of Pure Distilled Water, I have 30 mL in a total volume of 100 mL; Thus I could call this solution at 30 % v/v.
- I add 750 mL Ethanol to 250 mL Pure Distilled Water (750 mL in total volume of 1000 mL), I have Ethanol Solution at 75 % v/v concentration.
Few Miscellaneous Examples:
- Volume per Volume To Weight per Volume:
- I wish to convert “Ethanol Solution at 75 % v/v concentration” to “% w/v Concentration”.
Density of Ethanol = 0.789 g/ml.
- Mass of 750 mL Ethanol = 750 * 0.789 = 591.75 grams
- 75 grams diluted in Pure Distilled Water to make 1000 mL Solution
- This Yields a Solution of Ethanol at 591.75/1000*100 (or 59.1 % w/v concentration).
- Now suppose I add 35 grams NaCl to Pure Water such as to make a total volume of 100 mL, the final NaCl solution would be 35 % w/v.
- If I dilute “100 mL Pure 35 % H2O2” by adding Pure Distilled Water to make a total volume of 1000 mL Solution, I then get H2O2 at a concentration of 10 % v/v.
Now, let us go through two ways in which concentration of H2O2 is altered-diluted…
|1 part 35%||+||1 part water||=||2 parts 17.5%|
|2 parts 17.5%||+||2 parts water||=||4 parts 8.75%|
|4 parts 8.75%||+||4 parts water||=||8 parts 4.375%|
|8 parts 4.375%||+||8 parts water||=||16 parts 2.1875%|
So we may say, to 100 mL 35% H2O2 we add 1500 mL to get 2.1875% H2O2
Now, 50% Conc. H2O2 implies that in a 100 mL Solution, we have 50 mL H2O2, and 50 mL of Distilled Water.
Equation to use for concentration conversion is:
- x /(y + z) = w, where
- x = Amount of H2O2 in the initial amount of Concentrated Solution, which needs to be diluted to required concentration. So if we have taken 100 mL of 50% Conc. v/v, amount of H2O2 initially in the solution is 50 mL,
- y = Initial amount of concentrated solution (In this case we have taken 100 mL of 50 % Conc. H2O2 Solution, so y = 100),
- z = This is the assumed amount of water to be added to Initial Solution to get the final solution of required concentration and
- w = Required final concentration of H2o2 Solution.
- An Example:
- Let us say we wish to dilute 100 mL (y = 100) of 35% Conc. H2O2 to 3 % Conc. (=> w = 3% which we would write as w = 0.03),
- Let ‘z’ be the amount of water that needs to be added to get the required concentration,
- So the equation we get is: 35/(100 + z) = 0.03; This yields the value of ‘z’ to be 1066 mL, which is the final resultant amount of 3% conc. H2O2 Solution,
- Thus, we need to add 1066 mL of Pure Distilled Water to Initial 100 mL of 35% Conc. solution of H2O2 to get 1166 mL of 3% concentrated v/v H2O2 Solution.
My Choice for Food Grade H2o2:
Self-Procured-Diluted Further to 3-5 % Conc. Food Grade H2O2-Visit Web-page “Our Health Kit”
Legal Disclaimer: The information in this article is not a Medico-Legal advice. Use it at your own risk. Although I do my best to give you accurate and useful information, you should consult an appropriate Medical Professional before Trying out any of the above Information.