# Most powerful organic solvent **URL:** \ **Category:** Factual Questions\ **Created:** [September 19, 2012, 3:13am UTC](https://boards.straightdope.com/t/most-powerful-organic-solvent/635135 "2012-09-19T03:13:14Z")\ **Posts on this page:** 7\ **Page:** 2
**Author:** ![j\_sum1](https://avatars.discourse-cdn.com/v4/letter/j/8baadc/32.png) [@j\_sum1](https://boards.straightdope.com/u/j_sum1)\ **Post date:** [September 20, 2012, 5:01am UTC](https://boards.straightdope.com/t/most-powerful-organic-solvent/635135/21 "2012-09-20T05:01:30Z")
Ok. Colour me confused here. I thought that HF was a stronger acid than HCl. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [September 20, 2012, 7:01am UTC](https://boards.straightdope.com/t/most-powerful-organic-solvent/635135/22 "2012-09-20T07:01:57Z")
> [@j\_sum1](#): > > Ok. Colour me confused here. I thought that HF was a stronger acid than HCl. Isn’t hydrogen chloride highly hydrophilic? It’s very strong, but I’m not sure it’s better at dissolving lipids/oils than HF. ---
**Author:** ![dstarfire](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dstarfire/32/5762_2.png) [@dstarfire](https://boards.straightdope.com/u/dstarfire)\ **Post date:** [September 20, 2012, 7:55am UTC](https://boards.straightdope.com/t/most-powerful-organic-solvent/635135/23 "2012-09-20T07:55:36Z")
> [@Szlater](#): > > Just a little rhyme I made up whilst at school, for some reason we had to know how to handle fuming sulphuric acid… Without ever actually having to handle it. Congrats, you can now safely make gun cotton and smokeless gunpowder. 😛 ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [September 20, 2012, 11:07am UTC](https://boards.straightdope.com/t/most-powerful-organic-solvent/635135/24 "2012-09-20T11:07:05Z")
> [@j\_sum1](#): > > Ok. Colour me confused here. I thought that HF was a stronger acid than HCl. “Strength” of an acid typically refers to how well it dissociates in water. HCl has an estimated pKa in water of about -9, whereas HF is only 3.17. Strength only partially correlates to how bad it messes you up. Solvation breaks solute-solute and solvent-solvent interactions and forms solvent-solute interactions. You have to balance all of these (and entropy) when determining whether A is soluble in B. Polarity is just one influencing factor. Others are hydrogen bonding, π-stacking, fluorination. ---
**Author:** ![Szlater](https://avatars.discourse-cdn.com/v4/letter/s/90ced4/32.png) [@Szlater](https://boards.straightdope.com/u/Szlater)\ **Post date:** [September 20, 2012, 12:42pm UTC](https://boards.straightdope.com/t/most-powerful-organic-solvent/635135/25 "2012-09-20T12:42:22Z")
> [@dstarfire](#): > > Congrats, you can now safely make gun cotton and smokeless gunpowder. 😛 Party at my house? ---
**Author:** ![FoieGrasIsEvil](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/foiegrasisevil/32/16638_2.png) [@FoieGrasIsEvil](https://boards.straightdope.com/u/FoieGrasIsEvil)\ **Post date:** [September 20, 2012, 3:00pm UTC](https://boards.straightdope.com/t/most-powerful-organic-solvent/635135/26 "2012-09-20T15:00:26Z")
> [@WarmNPrickly](#): > > That doesn’t really contradict what I said. Fluoride reacts with glass whether it’s hydrofluoric acid or tetrabutylammonium flouride. It certainly doesn’t dissolve things due to its acidity. I could store it in plastic quite comfortably. Oh, I wasn’t trying to contradict you. I was joking. I use (diluted) HF quite a bit in my line of work (automated car washes…it’s an extremely effective wheel cleaner for brake dust). But it IS dangerous. I don’t allow my employees anywhere near it. > [@johnpost](#): > > before plastics it was stored in wax coated glass bottles. Ours is stored in 55 gallon drums. Its about 10% HF in the barrel, which is diluted by about half with water before its automatically deployed onto a car’s wheels in the wash tunnel. It wreaks havoc on the carbon steel in the conveyor though. We need to put an all stainless section there. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [September 20, 2012, 8:19pm UTC](https://boards.straightdope.com/t/most-powerful-organic-solvent/635135/27 "2012-09-20T20:19:35Z")
This question is like asking, “What is the best fitting aftermarket car seat slipcover?” and then arbitrarily picking a Jeep Wrangler as the test vehicle, so that the slipcovers made for Wranglers would of course win. The best solvent for some test substance is the one with the best affinity for that substance, which typically has a molecular structure that is very similar (though perhaps smaller so that it will be liquid). If you pick wax as your test substance, you are picking something typically with long and fairly unbranched chains of -CH2- molecular groups. The alkane solvents have molecules that look like that, though shorter than wax molecules, and pentane is pretty much the most liquid and most mobile of the alkanes that is still a liquid (not a gas). A common rule of thumb for dissolving any polymer is that its own monomer, or its dimers and trimers and other oligomers, are often among its best solvents. Pentane is more or less an oligomer of wax. If you want the organic solvent that will do the most damage to the widest range of organic solids, perhaps it would be a mixture of a big variety of small molecules (so that any solid will find at least a few molecules in there that are a good fit), and you’d get it very hot (so they are more active and have a lower surface energy so they wet and penetrate), and you’d also keep it under pressure so it didn’t just boil off. [Previous page](https://boards.straightdope.com/t/most-powerful-organic-solvent/635135.md?page=1)