Dr Thomas de Prinse undertakes the third step of his large-scale cubane synthesis, the bromination of the ethylene ketal of cyclopentanone to its tribromocyclopentanone derivative.

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A humorous look at FOOF by the inimitable Derek Lowe

This is not some sort of fancy new development, but it's such a classical experiment that it's always worth sharing IMO. Plus it's fun.

When you initially mix both solutions, nothing seems to happen. But once you wait a wee bit, the colour suddenly changes, from transparent to a dark blue.

There are a bunch of variations of this reaction, but they all boil down to the same things:

• iodide - at the start of the reaction, it'll flip back and forth between iodide (I⁻) and triiodide ([I₃]⁻)
• starch - it forms a complex with triiodide, with the dark blue colour you see in the video. But only with triiodide; iodide is left alone. So it's effectively an indicator for the triiodide here.
• some reducing agent - NileRed used vitamin C (aka ascorbic acid; C₆H₈O₆), but it could be something like thiosulphate (S₂O₃²⁻) instead. The job of the reducing agent is to oxidise the triiodide back to iodide.
• some oxidiser - here it's the hydrogen peroxide (H₂O₂) but it could be something like chlo

Dr Thomas de Prinse makes yttrium oxide doped with erbium and ytterbium.

Upconversion: Material absorbs two infrared photons, emits one visible photon.

A chemist told me rust does not spread. The top of my refrigerator gives me some doubt. It’s covered in these spots. The center of every spot is a small break in the paint, but the rust all around those spots is on top of the paint.

cross-posted from: https://lemmy.ca/post/39143995

The authors of the academic study, published in the Journal of the American Chemical Society on Thursday, had to get the smell from inside the sarcophagus without interfering with the mummy inside.

The researchers, from UCL and the University of Ljubljana in Slovenia, did so by inserting a tiny tube so they were able measure the scent without taking any physical samples.

If you want to smell the smell too

They say recreating the composition of the smells chemically will allow others to experience a mummy's whiff - and help to tell when the bodies inside may be starting to rot.

"We want to share the experience we had smelling the mummified bodies, so we're reconstructing the smell to be presented in the Egyptian Museum in Cairo," Cecilia Bembibre, one of the researchers, told BBC Radio 4's Today programme.

It's not really "professional" but you can look at the process, see the results and come to your own conclusion about it's viability.

[Maurycyz] points out right up front: several of the reagents used are very corrosive and can produce toxic gasses. We weren’t sure if they were trying to dissuade us not to replicate it or encourage us to do so. The project in question is making strontium aluminate which, by the way, glows in the dark.

The material grows strongly for hours and, despite the dangers of making it, it doesn’t require anything very exotic. As [Maurycyz] points out, oxygen and aluminum are everywhere. Strontium sounds uncommon, but apparently, it is used in ceramics.

Scott usually focuses on spaceflight and aviation topics, but there is some nice chemistry overlap in this video.

Dr Thomas de Prinse undertakes the first two steps of his large-scale cubane synthesis in his shed.

Another fantastic video from the OG YouTube Chemist.

Dr Thomas de Prinse announces his intentions to repeat his cubane synthesis on a larger scale.

I put an aluminum wok lid in the dishwasher and it came out with black marks on it. I’ve also seen other aluminum cookware come out with some kind of white powder specs on it.

So apparently aluminum is dishwasher unsafe. But obviously it’s not the water that’s the problem. It must be the detergent. So the question is, what can a lazy motherfucker like myself do? Why don’t I see aluminum-safe dishwasher detergents on the shelf?

Possibly related: Bailey’s creme liquor turns black underneath an aluminum cap. Is that a chemical reaction or spoilage, or something else?