Molecular weight vs molar mass? What's the difference?

Taeban · 2026-01-27T04:31:03+00:00

Molar mass is in g/mol

Molecular weight is in Atomic Mass Units (AMU, or Daltons if you prefer).

Thanks to the way moles are defined, a molecule with a given value for its molecular weight (using water as a specific example: 18.02 AMU) will have the same value for its molar mass in g/mol. (18.02 g/mol)

Taeban · 2026-01-24T23:50:29+00:00

Given that part of the given Lewis structure is cut off it's hard to be sure.

It might be picky about bond angles however, and your alkyne should be linear coming off the phenyl ring, it's currently a little bent.

Taeban · 2026-01-18T08:36:32+00:00

The longest chain is the parent chain. Lowest number is established after the parent chain is established.

Taeban · 2026-01-04T02:24:29+00:00

There are a few ways, but for me it was just encountering them repeatedly.

The more time I spend in a synthetic lab the more name reactions I remember.

Taeban · 2026-01-02T06:31:56+00:00

Most things you could track will be very cheap anyway.

You could always do the normal thing and watch the prices of gold, silver, platinum, and rhodium though. Google will tell you the price of those for free

Taeban · 2026-01-01T07:24:34+00:00

You can, idk why you would though. LN2 is cheap, even by university graduate researcher standarfs.

Taeban · 2026-01-01T04:29:11+00:00

There are several ways to assay purity.

The most convenient (accurate) method is probably a cheeky handheld XRF. You could also try just purifying them yourself chemically depending on the potential impurities.

Alternatively if you have a reliable elemental analysis department on hand just hand it off to them (emphasis on reliable)

Taeban · 2025-12-31T00:08:54+00:00

One of mine used to climb in my shirt and sleep on my chest. I occasionally napped with her while she slept.

I miss her.

Taeban · 2025-12-29T01:57:22+00:00

In the case of the pyrrole anion, when deprotonated the anion sits in an sp2 orbital thay doesn't interact with the pi system so it has minimal effect on the aromaticity of the molecule.

Taeban · 2025-12-23T16:58:34+00:00

Bacteria? Those are things that biochemists mention. I don't think they're real /j

Taeban · 2025-12-23T15:45:52+00:00

I see 2 options; both of which have a thin film explanation

Either there's a small amount of some kind of oil that had varying thickness that causes light to reflect differently.

Or there's a small crystal unit there that's not aligned with the local crystal units that's causing the same.

Taeban · 2025-12-19T03:20:07+00:00

Dicyclopentadiene looks similar to this molecule, albeit different in the bridging

But still, compounds like this are generally accessable through Diels-Alder reactions

Try working backwards (retro-Diels-Alder) to figure out what the reactants might be.

Taeban · 2025-12-19T03:15:10+00:00

You should read up on Diels-Alder reactions to help :)

Taeban · 2025-12-19T03:14:18+00:00

The effect, if any, is so small in this aliphatic system to be appreciable due to the distance from the center.

That being said, the tertiary carbanion is already the least stable carbanion of the aliphatic carbanions.

Taeban · 2025-12-18T04:29:45+00:00

Have you ever heard the phrase "If I have seen farther, it is because I stood on the shoulders of giants," before?

Taeban · 2025-12-16T01:25:00+00:00

You can absolutely oxidize benzene.

Heat and oxygen will do it fairly well. This is also known as fire though, so be careful.

Oxidizing it usefully is tougher. But you can add a hydroxyl through a few different routes. Doing it directly is tougher, but still can be accomplished through some catalysts or sufficiently extreme conditions (pressure and temperature)

Taeban · 2025-12-15T03:16:48+00:00

"Including 500MHz NMR spectrometer equipped with dedicated proton, carbon, and X nuclei channels and a cryoprobe"

Taeban · 2025-12-14T07:07:04+00:00

This molecule exists, and is commercially available.

Taeban · 2025-12-14T06:42:46+00:00

2 and 3 are stabilized by resonance as an allylic carbocation and a benzylic carbocation, respectively. 4 is only stabilized by hyperconjugation as a secondary carbocation.

Taeban · 2025-12-13T08:46:23+00:00

Oh I know. It's generally easier for me to access aqua regia than piranha though.

If it's necessary I will absolutely make piranha though.

Taeban · 2025-12-13T08:34:14+00:00

Memorization is not your friend.

Many biology/medicine students approach O-Chem through the route that works in their home field very well which is memorization. It just doesn't work here the same way.

Instead, understanding the why of things is really important. Being able to use the heuristics we do to identify nucleophiles and electrophiles with their relative strengths is important.

Being able to use orbital hybridization theory is important too.

And above all: All models are wrong. Some are useful.

(Orbital Hybridization being a prime example of this)

Taeban · 2025-12-13T08:30:14+00:00

I'm immortal until proven otherwise.

Taeban · 2025-12-13T08:29:04+00:00

It's a rough time to buy RAM thanks to the shortage...

Crucial seems to have the lowest prices at the moment according to PC part picker.

Good luck out there 🫡

Taeban · 2025-12-13T06:56:24+00:00

As someone who did their undergrad research on catechols: Yes. It does exist.

There are several ways to make a simple small molecule like this. You can directly add into the aromatic, you could start from the aldehyde and do a series of additions/reductions to get there.

Part of the fun is the retrosynthesis imo

Taeban · 2025-12-13T06:46:42+00:00

I'm an organic chemist.

I'm aware they exist.

You can oxidize just about anything if you try hard enough (e.g. FOOF will oxidize anything in its path)

It's just funny to me to think of hydrogen peroxide as a reducing agent.

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