I bought a chemical. The seller say it's mint ice. So I assume it's related to mint like menthol. It has odour. But it didn't melt, instead sublime.
It's soluble in 75% isopropanol. What is it?karlos³ - 12-9-2019 at 03:24
We need more informations to identify it.TmNhRhMgBrSe - 12-9-2019 at 05:00
It is white. Isopropanol solution is colourless. It is insoluble in water. What other informations you need?12thealchemist - 12-9-2019 at 08:43
You say it has an odour, but what does it smell of? I assume mint, but given you don't think it is menthol confirmation of odour could be indicative.
What temperature does it sublime at? Do you have access to any other solvents to test solubility?MrHomeScientist - 12-9-2019 at 10:33
Why'd you buy it if you didn't know what it was?
"Mint ice" suggests menthol, but who knows what they meant.TmNhRhMgBrSe - 12-9-2019 at 20:38
I buy it because I expect it to be menthol.TmNhRhMgBrSe - 12-9-2019 at 23:01
It's soluble in acetic acid, acetone, toluene, dichloromethane.
Insoluble in concentrated HCl and NaOH solution.TmNhRhMgBrSe - 12-9-2019 at 23:04
It turned into a colourless liquid when added to nitric acid. Temperature didn't change.
What's happening?
[Edited on 19年09月13日 by CELamCheng]TmNhRhMgBrSe - 12-9-2019 at 23:22
It burns with yellow flame and some black smoke.TmNhRhMgBrSe - 13-9-2019 at 00:22
Another weird observation:
It become another liquid layer when added to concentrated sulphuric acid. It also make concentrated sulphuric acid turn red. The temperature rise.
[Edited on 19年09月13日 by CELamCheng]Sulaiman - 13-9-2019 at 02:09
Besides menthol, mint contains Camphor, which could be what you have.
The easiest method of identification is smell - if you have menthol, camphor etc. to compare with.
fusso - 13-9-2019 at 03:53
Burns with yellow flame and black smoke? It should have a high C:H ratio. Maybe aromatic?12thealchemist - 13-9-2019 at 08:48
Do you have potassium permanganate? If you make up a very dilute solution of KMnO4 does the "mint ice" decolourise it? Do the colourless
liquids from the reactions with concentrated nitric and sulphuric acids make dilute KMnO4 decolourise?TmNhRhMgBrSe - 13-9-2019 at 22:30
"Mint ice"+KMnO4=no colour change
"Mint ice"+KMnO4+dilute H2SO4=no colour change
Colour from purple change to brown after very long time, maybe 1hr
[Edited on 19年09月14日 by CELamCheng]
[Edited on 19年09月14日 by CELamCheng]Tsjerk - 13-9-2019 at 23:24
With these results it can still be camphor right? Camphor won't be oxidized by cold diluted permanganate, also not when acidic. It probably doesn't
mix with concentrated sulfuric acid and it could very well turn red when mixed with sulfuric acid (at least acetone does turn red).
Also the solubility behavior sounds fine for camphor.TmNhRhMgBrSe - 13-9-2019 at 23:36
But wikipedia say its melting point is 175-177°C, and my sample don't melt, so is it really camphor?Tsjerk - 13-9-2019 at 23:59
But wikipedia say its melting point is 175-177°C, and my sample don't melt, so is it really camphor?
Camphor can be melted, but it very readily sublimes. If you put some in a large sealed bottle, and leave it in a warm place, do crystals of the "mint
ice" form around the top of the bottle?Pumukli - 14-9-2019 at 12:22
There's an old "trick" you can do with camphor: make a few mm long lengthwise cut starting from the bare end towards the head of a match stick.
Carefully pry open this slit and jam a bigger crystal of camphor into this opening. Basically it is a V-shaped slit that holds the crystal.
If you place this prepared match stick carefully onto the still surface of a bowl of water then the stick starts to move, as if the crystal was a
motor and the stick a boat - provided that the crystal actually touches the surface of water.
The movement is caused by the surface active property of camphor.
Menthol is relatively easy to oxidize. If you dissolved some in acetic acid (concentrated acid dissolves it well) then the solution would decolorize
permanganate quickly, probably in seconds. (Depending on the ammounts of chemicals used, of course.) Camphor should be resistant to this treatment.
