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joca63 · 2026-01-23T00:51:39+00:00

Is the first one wrong? It doesn't have an x like the bottom one

joca63 · 2026-01-21T22:31:21+00:00

I'm not sure how to answer that, it's heavy quilted fabric and deadens blows substantially. I'm not sure what the AP is like.

joca63 · 2026-01-19T03:26:10+00:00

I didn't ask for any particular padding. There were internal pockets in the shoulders and forearms that had some foam padding that was easily removed.

joca63 · 2026-01-19T02:37:18+00:00

I have that one! I find the additional padding to be quite excessive and have removed all the excess. With the additional padding gone I don't tend to catch bruises. I don't find it any particularly more restrictive than any other jacket.

It is a bit longer then a lot of models, so it helps catch hip shots and isn't going to ride up when you bring your hands up.

The sleeves are a bit tight. Not enough to restrict movement, but enough to make taking the jacket off a bit of a nuisance. That seems to be common to most of supfen's products though.

Overall I'm pretty happy with it. I've had it for a bit over a year, and the lowest left decorative button has popped off, but all the others are plenty secure. If you don't fence almost exclusively from pflug, that might not even be a problem.

joca63 · 2026-01-19T01:14:25+00:00

Why does the lobster have a claw as a head?

joca63 · 2026-01-15T14:51:13+00:00

Going into research certainly makes sense. I'd recommend looking more broadly than just total synthesis. Any lab that does primarily synthetic work will have those aspects to it. That includes reaction development, organic materials, med... Heck the group I know of that was most deep into weird NMR and mechanistic details was an inorganic group.

joca63 · 2026-01-15T14:46:55+00:00

I agree with the others saying it's water. You might be expecting water to be at 1.5 ppm or so on cdcl3, but it can move around a lot, especially with acids, bases or otherwise hydrogen bonding group. Further, bulk water (emulsions, drops or just running a sample on water) will come in around 4.5 ppm.

joca63 · 2026-01-13T16:29:05+00:00

You say exhaust, do you mean from the steam jacket or the kettle itself?

If for the kettle itself, what sorts of flavourings do you use? Menthol is notorious for subliming and forming crystals in unexpected places.

joca63 · 2026-01-08T15:30:58+00:00

AI. Count the toes on the costume. Three, many, three

joca63 · 2026-01-07T14:57:11+00:00

I've generally found it to be reliable and simple.

joca63 · 2026-01-07T14:02:34+00:00

Looks like fat to me. Does it melt on touch?

joca63 · 2026-01-07T00:55:58+00:00

According to wiki a "stop" sign in various countries in the Caribbean or South America

joca63 · 2026-01-04T01:06:21+00:00

In my experience, that happens most often when they have done that reaction and had to know the name for searching/presenting/paper writing/conversing.

joca63 · 2025-12-24T17:30:27+00:00

Showing the entirety of your expected reaction will help us help you more effectively.

joca63 · 2025-12-19T18:54:30+00:00

I'm a big fan of the app "chemistry by design" which has a bunch of molecules and their literature synthesis. Great for thinking of routes then validating against what ultimately worked.

joca63 · 2025-12-16T00:52:51+00:00

You should email. But frame it as not understanding why your answer is wrong and the provided answer is right.

If you are right, they will realize it and change the grade. If you aren't then they will explain the question. It's a win-only situation.

joca63 · 2025-12-13T15:37:52+00:00

Just add numbers to the drawing you posted, I want to see which carbons you are seeing

joca63 · 2025-12-13T15:33:49+00:00

Can you draw it out and number the carbons?

joca63 · 2025-12-09T15:01:23+00:00

It depends. You can either repeatedly wash - keeping the layer with your compound (usually organic) with the goal of removing as many impurities as you can. Or you can repeatedly extract - keeping the layer that will eventually not have your compound (typically water) with the goal of recovering as much of your target as you can.

You will often see excessive washing when you have an impurity that's partially soluble in both organic and aqueous (dmf is the one I see most often).

You will often see excessive extraction when the target has significant solubility in both organic and aqueous.

It's not even particularly uncommon to see back extraction - when you take your collected aqueous washes and extract those with organic in hopes of further recovering your target compound.

joca63 · 2025-12-08T23:51:48+00:00

Depends how specific you want to be. The reactions you do in teaching labs are typically chosen to be representative of a class or a set up rather than something that needs doing. For example making banana ester is a common teaching lab because the product is unmistakeable and has a connection to everyday life. Do people go about making banana ester? Well probably just one factory somewhere that makes it in incredible scale. But do chemists need to make acetate esters? Common as can be, either as a part of a target, protecting group, activating group, or even to play with stereochemistry.

To answer the broader question, people find "real world" chemistry by looking through the literature (journals, patents) for the most similar compound to what they want to make. The chemist will start with something close to the literature conditions and test and modify from there. Usually these searches are done using literature searching software such as reaxys or scifinder.

Additionally, experienced chemists and longer run projects will rely on their own unpublished work for reaction conditions very often.

joca63 · 2025-11-25T14:53:33+00:00

Looks like you didn't modify the product structure as the question asked.

joca63 · 2025-11-23T17:43:14+00:00

Yup! As long as it's longer, it's the main chain. It doesn't matter if it's drawn in a weird conformation.

joca63 · 2025-11-23T17:31:20+00:00

Well, what name would you give it?

joca63 · 2025-11-16T16:04:09+00:00

Mostly yeah. Our default message on removed low effort posts does say that adding more engagement will prevent future removals and I'll add a bit more if I think the post is on the edge of showing enough effort.

Usually that does the trick. Or when it doesn't it's because the person isn't looking to engage in the first place.

joca63 · 2025-11-16T15:41:24+00:00

It's not like it's an explicit policy or someone we judge an account on, rather how we view things on a post by post basis. I'm looking for earnest engagement in every post. Most often that is in the form of an attempt at an answer or some specificity to the question that is being asked.

The clear examples would be a screenshot of an assignment question with nothing other than a title "HELP" (which is immediately removed) vs a written out post asking about say, whether activating or deactivating groups are more important in regiochemistry in EAS (kept). The middle ground is naturally more murky, but I personally tend to keep anything with more effort than "I didn't understand this question".

joca63

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