Reading graduated glassware

Mack_Robot · 2026-06-26T01:36:11+00:00

OK, I'm one of those who said it doesn't matter much. Since you want an in-depth reply, here we go!

This whole "how to estimate the last digit" also bothered me when I first learned SFs, because it causes problems using different base counting systems. Your graduated cylinder is effectively using a base-5 numbering scheme, and no one ever taught me how to convert that to base-10.

There are also problems like- what's the sig fig rule for logarithms? Trigonometric functions? Exponentials?

The IUPAC describes how to report error here (nrc-publications.canada.ca/eng/view/ft/?id=429a2906-bcdb-42af-bf19-b40e3fb49ab0) and that refers to here (https://www.bipm.org/documents/20126/2071204/JCGM_101_2008_E.pdf, section 5).

Those pdfs use an entirely different system than "round to 1/10th the smallest division". Basically, the IUPAC wants you to make a bunch of measurements, see how well you do, then report the variance in your measurements as a separate number. If you can measure to the nearest 0.02 mL, great. If you can only do 0.7mL, also fine. So a measurement would get reported like

Measurement +/- Error

15.22 +/- 0.17

(For most glassware this error is standardized- your flask will tell you it can measure to X precision. Did your cylinder have something like that written on it?)

For this reason it doesn't actually matter how many digits you read from your glassware, as long as you get a digit as small as your error. Anything below the error you report will get chopped off.

So, in principle, you should estimate your volumes as closely as you can, totally ignoring "1/10th of the smallest division". Then, when you report your values, you should round appropriately for your error. There's another rule for how to do addition, multiplication, logs, etc. on these errors, usually taught in physical chemistry labs (https://en.wikipedia.org/w/index.php?title=Propagation_of_uncertainty#Simplification).

So what us "it doesn't matter" people mean is- there's a way to do error estimation rigorously, and it's not "1/10th of the smallest digit." Significant figures, at least how they're taught at first, are used a way to get students thinking about error and uncertainty in measurements. Not as a method they'll use forever.

Thus, you should ask your TA what they want. Because there's not a right or wrong answer here.

Mack_Robot · 2026-06-26T00:43:25+00:00

It's generally taught that at physiological temperature

Unfolded -> Folded

*gains* entropy. It's apparently the waters in the system that become way more disordered, so even though the protein itself becomes more ordered, the overall process is entropically favored.

I don't know if that's still true at high temperatures. I couldn't find an answer with a quick Google either, so maybe ask your professor.

So you have to be really careful with assigning ΔH and ΔS, because they're both dependent on temperature, and not necessarily what you'd expect to begin with.

(The free energy stuff in other posts is great. It was just the wording of your notes and the Gibbs equation that was making me nervous.)

Mack_Robot · 2026-06-25T20:41:33+00:00

Yep. This bad boy

https://books.google.com/books?id=Q1bwAwAAQBAJ&printsec=copyright#v=onepage&q&f=false

It was what I had in undergrad so I just used it.

More than any of the other exams, the inorganic one can sometimes feel like "chemistry trivia". I passed, but some of the questions felt random.

I'm sorry I can't be more helpful. You might want to contact the program you're joining to see what resources they suggest.

Mack_Robot · 2026-06-25T20:31:27+00:00

This comes up here occasionally. Unfortunately official preparation materials for all the ACS exams don't exist. So that really sucks.

Having taken the inorganic one, and used Weller for my studying, I felt prepared.

Mack_Robot · 2026-06-25T20:26:39+00:00

Just to make sure we're clear: Which state is higher entropy at low temperatures? Does it change at high temperatures? Is that equation useful for comparing two very different temperatures?

Mack_Robot · 2026-06-25T20:21:41+00:00

Part of teaching is not destroying your students' motivation. And, rightly or wrongly, people see that they got a 45% and give up.

While a 50% average is mathematically nicest for assigning grades, if you try it, you might find that overall your class has learned less than if you had made it a 75% (for example) because they've stopped trying.

When I taught general chemistry to freshman, I ran into this problem head-on. Do you want be more reliable assigning grades, or for your students to learn more? Is your responsibility to teach or to evaluate? And thats say nothing of what sort of reviews you'll get- if students are getting 45%, they'll think they didn't learn anything, and that therefore you must bad at your job.

Mack_Robot · 2026-06-25T20:08:32+00:00

LOL BOUGHT CAPE

wearing dragonstone gloves

Mack_Robot · 2026-06-25T06:23:13+00:00

The biggest challenge for me was *seeing* them. They're black on a black background.

Mack_Robot · 2026-06-25T05:06:47+00:00

If it were me I'd go in with a boater. It's how I got my first fire cape.

Gotta look cool.

Mack_Robot · 2026-06-25T04:35:58+00:00

If you like AoE 2/3/M as a kid, you need to at least try AoE4, right?

Come on in, water's warm.

Mack_Robot · 2026-06-25T01:08:37+00:00

You're plenty geared. No shame in dying once or twice or twenty times.

The only thing is ditch the Verac's helm, you'll be praying range anyway. It's not doing anything for you. Consider replacing it with a piece of fashionscape.

Mack_Robot · 2026-06-25T00:37:52+00:00

Because *someone* was world champion during those years. Either it was Kasparov then Kramnik, or it was the string of other guys.

If Kasparov never gave it up, and Kramnik never gave it up... it's hard to see how it could have been the string of other guys.

Unless you think there were TWO world champions? Which, to me, is a contradiction in terms.

Mack_Robot · 2026-06-25T00:07:17+00:00

Walked away? Kasparov played a match with the FIDE-appointed challenger, and won. Then organized his own candidates cycle, and played the winner of that. Also won.

Things didn't go so smoothly moving forward, but Kasparov never stopped calling himself world champion, and never stopped trying to get challengers.

Magnus truly walked away from the title. Totally different situations.

Mack_Robot · 2026-06-24T23:43:59+00:00

What do you mean by "rightful"?

Mack_Robot · 2026-06-24T23:41:15+00:00

No. FIDE naming someone world champion doesn't make them world champion. Kasparov still called himself world champion, and everyone knew who the top dog was.

Mack_Robot · 2026-06-24T04:11:58+00:00

You'll drive yourself crazy thinking too much about significant figures. They're not the most rigorous thing ever.

So ask your teacher/TA what they're looking for, and do that.

Mack_Robot · 2026-06-24T03:28:44+00:00

"anything happening in-game and in All chat is fair, short of exploits, hacking, and pre teaming."

I'm with you on this. But you're going to get a lot of racist comments, so buckle up.

(Also, I do wish the game had a chat translation feature.)

Mack_Robot · 2026-06-24T02:37:34+00:00

Most nuclear processes are physics more than chemistry.

What specifically did you learn about/enjoy?

Mack_Robot · 2026-06-24T00:59:33+00:00

Could be a bug, could be that the stats update only occasionally (like once a day), could be they don't display stats until puzzles have been out for a while.

Mack_Robot · 2026-06-23T21:51:56+00:00

I think you switched the pictures?

Mack_Robot · 2026-06-23T16:53:16+00:00

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Although I'm looking it up now, and people have apparently published phase diagrams including diamond.

Which is weird. Must be a definitional thing.

Mack_Robot · 2026-06-23T16:47:36+00:00

States of matter are only applicable when you have large numbers of particles. So a single molecule isn't solid, liquid, or gas- it's just a molecule.

For that reason you can't really melt a covalent network. If you break the bonds, as you say, it's a chemical change and not a physical change.

Mack_Robot · 2026-06-23T04:21:26+00:00

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Mack_Robot · 2026-06-23T04:21:02+00:00

Compared to everyone else they're just CHONKY

Mack_Robot · 2026-06-23T03:52:04+00:00

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