How to Determine Correct Percentages for Diluting Potash in Electrolysis Device?

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The discussion focuses on calculating the dilution of a potassium hydroxide (KOH) solution from 45% to 28%. The user seeks to determine the correct amount of water to add to achieve this dilution. Starting with 1 liter of 45% KOH solution, the user calculates that to reach a concentration of 28%, approximately 1.57 liters of water must be added. The calculation involves determining the weight of KOH and water in the solution and solving for the volume of water needed to achieve the desired concentration. Additionally, a suggestion is made to use CASC, a tool designed for such calculations, to simplify the process.
dkmacmillan
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Hello all,
This is my first post here. My apologies if this is in the wrong place.
I'm building an electrolysis device using potassium hydroxide (KOH) as the electrolyte and I don't know the formula for determining the correct percentages.
I'm trying to dilute caustic potash from 45% KOH & 55% water to 28% & 72% respectively.
The weight is 1441.5 grams per liter (gpl).
 
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Let's say that you start with 1L of 45%( that's by wiehgt, I'm guessing) solution and add x cc (=x gms) of water. You now have 450 g KOH with (550 + x) g H2O. So, the new dilution is 450/(550+x) = 28%

Solving for x gives, 0.28x = 450 - (0.28*550) = 296, or x = 1057.143 cc or 1.57 L

So, for every liter of solution, you must add 1.57L of water to get to the right dilution.
 
Thanks you're a big help!
 
Try CASC, it does exactly such calculations.
 

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