How potassoim hydroxide is identified in the laboratory?
It would be great if you could give me a reference.
Thanks a bunch!!
Answer:
"By the label on the bottle" -- nah, you don't want a smarty-pants answer...
If you have a good amount to spare (say, 0.2 g or more), you can do good old-fashioned qualitative analysis. There's a protocol for eliminating all other cations and anions from consideration (see any standard text on qualitative analysis. We used "Introduction to Semimicro Qualitative Analysis" by Sorum and Lagowski), but in the end, you KNOW potassium is there when you do a flame test: dip a nichrome wire loop into the solution and apply it to the Bunsen flame. View the flame through cobalt glass (this dark blue glass), and if the flame looks pinky-purple, that's potassium. The cobalt glass is necessary to filter out yellow flame produced by sodium contaminants. I've also heard of (but never used) a reagent called "Kalignost", which is a sodium tetraphenylborate salt that precipitates potassium tetraphenylborate from the solution. Heaps of other cations will precipitate as a tetraphenylborate salt too, so this is used only after all other metal cations are removed, and mainly for quantitative analysis.
Hydroxide is inferred after all other possible anions are eliminated (i.e., test the sample for everything else. If all negative, you must have a hydroxide). As others have mentioned, you can test some of the solution on red litmus paper. KOH is basic, and will turn the paper blue.
Oh, y'mean Lye!
Potassium Hydroxide (KOH, Lye, Potash) is super alkaline - that is, it's a base. When I was little, my mom used Red Devil lye to clean the drains in our house, it's that strong. So you could do a pH test, for one.
http://en.wikipedia.org/wiki/potassium_h...
http://www.osha.gov/dts/chemicalsampling...
Hi Jean C,
potas'sium hydrox'ide, chem KOH a white substance, deliquescent solid. used chiefly in the manufacturing of soap, as a laboratory reagent, & in medicine as a caustic. Also call potash, potas'sium hy'drate. My youngest daughter took chemistry in high school & I'd have to say drove me crazy with all the tables,signs, now she is in college & took it again basicly you want to know the tables most helpful study partner that's had chem. 1 & 2. Good luck & have a good day. :0)
A very simple test would be to allow a sample of air to pass over it.Carbon dioxide present would be absorbed by it.Now the air coming out of the solution is allowed to pass through a solution of calcium hydroxide.We if the solution(second one) turns milky that means the original solution was not KOH.If the the solution does not turn milky then the solution(first one) was KOH.
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