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Author: Subject: Everyday Chemistry (provisional)
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[*] posted on 1-1-2022 at 20:05


Friends insisted that we make some fire for new years so before the celebration began i showed them what a 10 monutes of nitration will do to a 3 grams of cotton. Shot @ 800fps.

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[*] posted on 5-1-2022 at 20:32


In my attempts to be conscientious, I have numerous solutions of waste waiting to be recycled. Today was the day for at least some of them.
I am discovering that many of them are quite dilute and need litres of boiling down before recovery can be done. I am slowly becoming convinced that it is not worth it for just a few grams of iodine or barium hydroxide.

Nevertheless, it has been a pleasnt day in the lab and I have been working my way through chemplayer videos again.
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[*] posted on 9-1-2022 at 00:50


Damn I like it when things work out nice.

The other day my new set of scales arrived and so it was time to properly titrate the HBr that I synthesised last week.

I made a rough initial estimate which was basically pulling a figure out of thin air based on my guess of how much of my distillate came over at azeotropic temperature.
Then I measured density. But not having a density table for HBr I used the one data point available for azeotropic and assumed the curve would be the same as HCl.
I then pulled out the volumetric flasks, pipettes and burette and got going.

Nice correlation between all three figures -- certainly within measurement error.
Estimate 30%
Density 30.45%
Titration 30.65%

I don't have a fancy label for the bottle. But even my hand-written sticker felt like an achievement badge.
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[*] posted on 9-1-2022 at 19:41


j-sum,

There are density tables for most common acids and bases and related solutions in the back of Vogel "Practical Organic Chemistry". I believe that various editions of this book are easily available.

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[*] posted on 23-1-2022 at 10:06


I just ran a distillation of chloral from chloral hydrate and sulfuric acid.

Now running the reaction of chloral and fluorobenzene with sulfuric acid. The 1947 procedure I'm following calls for oleum, so I added some P2O5 to my sulfuric acid.

I was supprised by the exotherm between the P2O5 and 96% sulfuric acid.

Attachment: bradlow1947.pdf (431kB)
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Edit: I love my IKA mag stir, my reaction is running in a five degree shed, the 100 ml round bottom is in a couple 100 ml water in a beaker rapped in alu foil. I just put my mag stir set to what I supposed to be about between 20 and 30 degrees. Has been between 20 and 25 for hours now.

[Edited on 23-1-2022 by Tsjerk]
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[*] posted on 24-1-2022 at 23:43


I need a coolant system to get below 25oC :)
.................................
Unrelated, current mini-project:
For reasons still unclear to myself,
I recently recrystalised commercial potassium nitrate multiple times to 'purify' it.
(a few mini-fireworks made with used 120mm filter papers)
Problem is, I don't know the initial or final purities.
Everything I observed makes me 'think' that the original kno3 was/is quite pure.
(no sediments, colors, change in crystal shapes etc)
Some research reqd.




CAUTION : Hobby Chemist, not Professional or even Amateur
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[*] posted on 15-2-2022 at 21:35


Took my recently acquired heating mantle/variac for a spin, steam distilling citrus peels ... all went smoothly



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[*] posted on 16-2-2022 at 02:39


Tried to extract, purify, and dry anthocyanin. Sourced from red cabbage, beats, and then finally amazon. This molecule is very, very easy to destroy/decompose. I wanted to test it as a catalyst for the "alcohol catalyzed perduction of sodium metal" reaction.

Extraction was easy. Drying was not.
After 20 drying experiments, which decomposed the anthocyanin, I used store bought freeze dried.

Exposure to mineral oil from the same bottle of oil and anthocyanin from the same bag perduced verying results each time. Solved by bubbling h2 through the oil with 200c heat under vacuum (-15inhg) for 1 hour to clean/dry the oil

Test tube:
Exposure to sodium jump start at 105c produced a passiveation layer (brown oil) on the sodium and bottom on the flask. Sometimes, the sodium could be brought to the top of this layer and reacted more, but soon was covered again.

25ml round bottom flask:
Heavy stirring was added, and the results were a thick brown layer. Additions of magnesium metal produced a hard, solid black tar after a few minutes.
I added NaOH even with the listed problems. The tar that resulted was difficult to remove and contain unreacted sodium metal. 10% H2SO4(aq) was able to remove it with violent effectiveness

I think instead of working to find an easier to obtain catalyst, I will search for a more available reducing agent. Magnesium is not as cheap or as available as other metals. Aluminum should not work, so I'll start their. My thoughts on this are: Magnesium shouldn't work because it's lower on the reactivity series. NaOH + Mg = Na + MgOH works.
I know aluminum and sodium will produce an almogum, but maybe an excess of sodium hydroxide will be able to separate the mixture and force the reaction to completion. Baby steps.




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[*] posted on 14-3-2022 at 03:48


Recrystallizing some vanillyl oxime now to reduce with U-Ni-NH3 made in situ with zinc. I didn't look at what method to use for the oxime reduction, only to realize I could probably also directly aminate vanillin with this method. So I will just try both.

Is there an amateur capsaicinoid synth with actual characterization around? I could only find the one below, but it is without characterization of the product or intermediates. Also on YouTube nothing found, only preps for the precursors.

https://www.sciencemadness.org/whisper/viewthread.php?tid=23...

Waiting for octanoic acid and triphenylphosphine to arrive to make octanoyl chloride with TCCA.

[Edited on 14-3-2022 by Tsjerk]
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[*] posted on 16-5-2022 at 13:07


So I tried nitrating p-anisic acid. Dissolved 1.22 g of it in 20 mL acetic acid, added a mL each of nitric and sulphuric acids. No change. Heated to dissolve everything, let it stir for an hour or two, gave a white precipitate when it cooled down. Several cycles of adding more nitric, adding more sulphuric, stirring it overnight, heating to 70 C or so, etc, and finally cooled it down, added 100 mL water, and filtered. The precipitate was white (I expected yellow, like nitrobenzoic or nitrovanillin), and gave a mp of 188 C when dried. Really close to the lit mp of p-anisic acid, so I figured it was a failure.

Then I did a mixed mp of it with the original p-anisic acid. It's not p-anisic acid, and the lit mp of the nitro compound is 195 C. So it's the product I wanted (I think)- it just needs recrystallization.

This is the first time I've gotten useful information out of a mixed-melting point since first year organic chem.

[Edited on 16-5-2022 by DraconicAcid]




Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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[*] posted on 25-5-2022 at 17:55


Taking a break from trying RustyShackleford's ethylenediamine prep to steam distill some orange peels. Also got a nice crop of crystals of trisodium citrate, after many months of slow evaporation :cool:

I've been dissolving a bit of gallium in some hydrochloric acid, and the temperature outside keeps going back and forth across its melting point. I expected it to dissolve faster when warm, but when the metal is molten I see no hydrogen generation. When its cool there is a gentle stream of very small bubbles. Weird




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[*] posted on 8-6-2022 at 15:46


Done this with a 4, 8, and 10 year old. They love it.
To the best of my knowledge, this is food-safe chemistry. Don't eat it. Clean up with soap and water.

Vinegar, baking soda, and food coloring is a good one. Old school volcano demonstration. A saturated solution of baking soda gives the best effect.

CH3COOH + NaHCO3 → (CH3COO)Na + CO2 + H2O

After you're done. Dry the liquid to collect the sodium acetate you just formed. By using a cooking pot and gentle heating. Try not to exceed 150c.
Do not boil to dryness. Use a spoon to stir the solution. A good stopping point will be when you remove the spoon and it has solids form on it.

You will collect a liquid colored with your food coloring. Slowly let it cool.
At room temperature get the liquid and slowly pour it onto the solid on your spoon. As you pour it, it will grow a tower.

Next, you can show the children how to remove the food coloring.
Slowly heat the solid until almost all of it had turned into liquid. Then let it cool.
By keeping a few crystals in the liquid the solution will be less likely to supersaturate, allowing crystals to form slowly. As the cooling continues, you will have to judge for yourself, you can pour off the liquid and have white crystals left over.

Congratulations !!! You have just performed an acid-base naturalization of an organic acid and purification of your product. And the children chant, doves fly, and the science fair was a success of not a hot mess




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