What is the PH range between 58 grams and 87 grams of Sodium Hydroxide in 6 oz by volume of water. What is the PH range of that amount of Sodium Hydroxide in 8 oz of water. I need this information to learn to make soap using wood ash.

Answer 1

Is that 6 fluid ounces or 6 ounces dry measure?. The measure is slightly different but I don't think that will make any difference in soap making. 1 ounce (mass) = 28.35 grams; therefore, 6 ounces = 170 grams and 8 oz = 227 grams.
I should point out that if you are making it with wood ash, you will be using KOH and not NaOH.
moles NaOH = 58/40 = 1.45.
Assuming that adding NaOH to 170 mL water doesn't change the volume of the water (not exactly a good assumption), then
M NaOH = 1.45/0.170 = 8.5 M OH^- which gives you a crazy number like -0.93 for pOH and 14.93 for pH (remember the scale only goes to 14). None of that really makes sense anyway because in a concd solution such as that the pH doesn't mean very much. Remember, too, that if you are using wood ash for the KOH, that will not be pure KOH. Technically, it is K2O (and only a small percentage at that) in the wood ash and becomes KOH when dissolved in water.
87/40 = 2.17 moles and
2.17/0.170 = 12.8M for OH^- and the pH =15.1.
If you want to recalculate for KOH, use 56 for the molar mass KOH instead of 40 for NaOH.
Follow the above for the 8 oz (227 grams). The numbers won't be that different.

Answer 2

I know how to make soap, using lye. I want to be able to make the lye solution from wood ash be the same ph as commercial lye. I think this can be done using the ph of sodium hydroxide in water as I first stated. Is it possible to compute this ph.

Answer 3

I need to duplicate the strength of lye made from wood ash dissolved in water (Potassium Hydroxide) to that of lye made from Sodium Hydroxide disolved in water. The soap recipes I use require lye of various strengths as determined by fluid volume of water combined with the prescribed humber of grams of sodium hydroxide. e.g. 6 fluid oz of water combined with 58 g of sodium hydroxide. This makes lye of a specific strength. I want to be able to duplicate the strength of the sodium hydroxide lye water when useing potassium hydroxide made from dissolving wood ash in water. I can make the potassium hydroxide lye water stronger by reducing its volume with heat or weaker by increasing its volume by adding more water. I assume the easiest way to make potassium hydroxide lye water of the same strength as the sodium hydroxide lye water is to make them have the same PH. To do this I need to know the PH of a solution made from 6 fluid oz of water combined with 58 gr of sodium hydroxide.