Extraction Of Lye From Ashes
*Notes regarding a successful attempt to extract and concentrate (possibly) sodium hydroxide.
For an end result, it wasn't too bad. As an experiment, it was a horrible attempt. Since this was a first run, I was lax in any sort of proper procedure in regards to documentation or organization of that procedure. As it is one of the easiest chemicals to produce I didn't think to approach this with the seriousness that could have given me the opportunity to practice the skills of observation and record keeping needed for a scientific discipline.
So the lesson I learned was to approach every experiment with those principles in mind.
The ashes were obtained from burning the hardwood found in the park (incidentally, from my post about cooking beans) and from a friend's bbq grill, which was commercial charcoal. After settling I had about a 1/3rd full sauce pan and some hardwood charcoal chunks.
After letting it soak for a few hours on the stove on medium heat, I went through the process of straining out all the water (by using a ladle and coffee filters stretched over the collection cup) and separating the material (the mostly pure, silt, and chunks) into different tall cups. I continued to soak the material from each of the cups and straining it into the saucepan in a simmer/boil.
Observations:
7-18-11
* Despite the amount of soot present in the slurry, spills were surprisingly easily to clean, leaving behind no residue.
* The fine silt quickly settled to the bottom from the rest of the solution. The fluid resting on top was clear.
* Did leave a waxy residue on the hands. Which I found strange, considering that the fluid was as viscous as water and left no tacky residue when dried.
(Upon further reflection of this fact, I hypothesize two likely explanations, one, that the lye was actually breaking down the oils on my hands, a sort of local saponification, or two, more likely seeing as my hands were constantly run under water and very little oil was present, that it was breaking down the top layer of skin.)
7-18-11
* After 5 days no noticable amount of fluid has evaporated despite being subjected to the summer sun all day. I think this confirms the NaOH's hydrophilic properties.
7-26-11
* After 8 more days, a drop of about 2% of volume has occurred.
* The solution maxed out the pH test strips I obtained, ensuring that it is, at the very least, 8.4 pH.
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Persisting Questions:
I still don't know the exact pH of this solution. The test strips I had were crappy overpriced ones designed for aquarium usage (but, hey, surely I get points for even being able to find something that tests pH in walmart.) I think I'll spring for the real kind, but thinking about this makes me wonder if their is a mathematical formula for taking a diluted solution (getting the pH in the range of the test) and figuring out how much reduction of volume would be needed to increase the concentration....?
Also, I'm not exactly certain that I have sodium hydroxide, for it could be potassium hydroxide, which it is often confused for, or some other mixture. I must find more tests to apply to the solution to determine its exact makeup.
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