Search found 28 matches

by TychoMaudd
Mon Jun 22, 2015 1:53 pm UTC
Forum: Science
Topic: Partial charge calculation of Hg
Replies: 7
Views: 2939

Re: Partial charge calculation of Hg

It's not IMPOSSIBLE to arrange a partial charge on a lone atom - you can arrange a state in which it has wavefunction components with different charges. But because you aren't in the usual molecular system, other things are going to dominate and the approximations it would tempt you to use are mean...
by TychoMaudd
Thu Jun 11, 2015 2:03 pm UTC
Forum: Science
Topic: Partial charge calculation of Hg
Replies: 7
Views: 2939

Re: Partial charge calculation of Hg

Even with an external field around it, a lone atom shouldn't carry a partial charge. The charge distribution around the atom may change (eg. induced dipoles) , but the overall charge of the atom won't. A lone atom doesn't have molecular orbitals to distribute the charge over, either the atomic orbit...
by TychoMaudd
Wed Jun 10, 2015 3:44 pm UTC
Forum: Science
Topic: Partial charge calculation of Hg
Replies: 7
Views: 2939

Re: Partial charge calculation of Hg

How would a single lone atom hold a partial charge? In a molecule partial charges exist because of uneven "sharing" of electrons. With a single atom I'd think that it'd be in whole number oxidation states loosing (or gaining) one electron at a time.
by TychoMaudd
Fri Aug 30, 2013 2:33 pm UTC
Forum: Hardware
Topic: Buying new laptop
Replies: 6
Views: 4839

Re: Buying new laptop

I don't have the x230, but I do have the slightly older x220 (main difference being sandy bridge vs ivy bridge and the new keyboard). I absolutely love my x220, I got it with the larger 9 cell battery and it can last ~10hr webbrowsing, ~5-6 playing video, and about 3 playing a game like fallout 3. I...
by TychoMaudd
Thu Aug 15, 2013 9:30 pm UTC
Forum: Science
Topic: Solubility in (tap) Water
Replies: 21
Views: 6362

Re: Solubility in (tap) Water

If water at room temperature will not loose oxygen sitting out, why do goldfish drown if their water does not circulate? Because the goldfish use the oxygen in the water, and more doesn't instantly dissolve in from the atmosphere, it take some time unless you increase the partial pressure of oxygen...
by TychoMaudd
Tue Aug 13, 2013 11:45 am UTC
Forum: Science
Topic: Solubility in (tap) Water
Replies: 21
Views: 6362

Re: Solubility in (tap) Water

While dissolved gasses will affect the taste of water (especially CO2), heating water to boiling or near boiling will drive off most of the gasses. Water in most plumbing systems is under pressure, and as such can contain more dissolved gasses which want to come out when it's open to the atmosphere....
by TychoMaudd
Fri Jun 14, 2013 2:45 pm UTC
Forum: Science
Topic: Worst thing you've seen in a lab
Replies: 256
Views: 233212

Re: Worst thing you've seen in a lab

Organic solvent vapors can permeate and be absorbed into a contact lens. This causes the concentration of organic solvent in the lens to be higher than the vapor that your eye would be exposed to normally. It is possible to have enough dissolve into the lens to cause it to deform, but even more dang...
by TychoMaudd
Fri May 31, 2013 6:48 pm UTC
Forum: School
Topic: My school fails at computer security...
Replies: 314
Views: 117859

Re: My school fails at computer security...

Mac OS 9 had no inherent file permissions and everything essentially ran in kernel mode. Seriously? That's awful. How did they even do that? Didn't OS9 inherit from BSD? MacOS X is based on BSD, replacing the classic Mac OS. But everything up to and including MacOS9 was basically just built up from...
by TychoMaudd
Thu May 30, 2013 2:48 pm UTC
Forum: School
Topic: My school fails at computer security...
Replies: 314
Views: 117859

Re: My school fails at computer security...

When I was back in highschool, the school district tried to keep computers secure, but ran into a big problem with running the MacOS 9. Mac OS 9 had no inherent file permissions and everything essentially ran in kernel mode. The security system used tried to intercept commands from the System and Fi...
by TychoMaudd
Fri Feb 08, 2013 4:52 am UTC
Forum: Science
Topic: Worst thing you've seen in a lab
Replies: 256
Views: 233212

Re: Worst thing you've seen in a lab

Given that we're somewhat adapted to out own stomach acid I'd b more concerned about an excess of the base. What would a pH of 11 or 12 do to the throat? The same thing that a pH of 1 or 2 would. Note that you'd have to get the experiment spectacularly wrong for either thing to happen. I think it w...
by TychoMaudd
Fri Nov 30, 2012 7:27 pm UTC
Forum: Mathematics
Topic: A Statistics Question
Replies: 0
Views: 1507

A Statistics Question

I'm an analytical chemist with some experience in statistics, but not much more than an intro level course. The other day my boss posed a question for me, what is the smallest sampling size of a chemical solution that will avoid random sampling error? I figured that I could frame it as a binomial di...
by TychoMaudd
Fri Oct 19, 2012 3:31 pm UTC
Forum: Science
Topic: Have you ever worked with hydrofluoric acid?
Replies: 30
Views: 13154

Re: Have you ever worked with hydrofluoric acid?

I haven't ever purposefully used HF for anything, but I have had reactions that produced it as a side product (Using BF3 in a reaction, halting it with H2O, produces HF). Thankfully it was in small millimolar quantities, and the next thing done was to immediately neutralize it with saturated sodium ...
by TychoMaudd
Sun Jul 08, 2012 1:53 am UTC
Forum: Science
Topic: A question about nitrogen
Replies: 6
Views: 3903

Re: A question about nitrogen

In the azide ion, the middle nitrogen carries a positive charge, in essence, lending an electron to one of the other nitrogens, leaving it with 4 valance electrons to form 4 bonds.
by TychoMaudd
Sun Jul 08, 2012 1:03 am UTC
Forum: Science
Topic: Worst thing you've seen in a lab
Replies: 256
Views: 233212

Re: Worst thing you've seen in a lab

] Sugar does melt - the trouble is more that sugar has sucked up a lot of water in its normal form - so it actually goes liquid pretty easily, but then it boils off a lot of water. So when the temperature jumps (like from 120 C to 160 C), that means you've finished boiling of the water, and need to...
by TychoMaudd
Sat Jul 07, 2012 1:49 pm UTC
Forum: Science
Topic: Worst thing you've seen in a lab
Replies: 256
Views: 233212

Re: Worst thing you've seen in a lab

In primary school, my physics teacher tried to measure the melting point of sugar. The thermometer went like 80°C - 120°C - 160°C - and then the tip of the thermometer melted off. (He then commented that we had observed a phase transition from the solid phase to the smelly phase.) What kind of ther...
by TychoMaudd
Mon Jun 25, 2012 11:15 am UTC
Forum: Science
Topic: Worst thing you've seen in a lab
Replies: 256
Views: 233212

Re: Worst thing you've seen in a lab

We've got Pt crucibles no bigger than a thimble that cost over $1000 each. A whole crucible? What do you do with them? They generally get used for USP/NF ID test for silicon dioxide. It involves heating the sample and potassium carbonate in a Pt crucible until they melt together, then adding in 2 m...
by TychoMaudd
Sun Jun 24, 2012 11:57 pm UTC
Forum: Science
Topic: Worst thing you've seen in a lab
Replies: 256
Views: 233212

Re: Worst thing you've seen in a lab

Back in Chem 101 lab at college, we had an experiment that involved (slowly) dissolving a small amount of sodium in water to produce sodium hydroxide. This was done by putting the sodium in a filter paper and slowing adding water over it until it was fully dissolved, then the filter paper was discar...
by TychoMaudd
Fri Jun 22, 2012 5:20 pm UTC
Forum: Science
Topic: Worst thing you've seen in a lab
Replies: 256
Views: 233212

Re: Worst thing you've seen in a lab

We've got Pt crucibles no bigger than a thimble that cost over $1000 each. A whole crucible? What do you do with them? They generally get used for USP/NF ID test for silicon dioxide. It involves heating the sample and potassium carbonate in a Pt crucible until they melt together, then adding in 2 m...
by TychoMaudd
Fri Jun 22, 2012 1:22 am UTC
Forum: Science
Topic: Worst thing you've seen in a lab
Replies: 256
Views: 233212

Re: Worst thing you've seen in a lab

man, i can't tell you how often i see people break cylinders, beakers, flasks, etc. i didn't think much of it before, but then i began to consider doing a bit of home chemistry for fun. the prices on some of those things... dear god... fortunately a large state school always has money to blow even ...
by TychoMaudd
Wed Jun 20, 2012 12:36 am UTC
Forum: Science
Topic: The answer! The answer! My internets for the answer!
Replies: 19
Views: 4816

Re: The answer! The answer! My internets for the answer!

The force of friction (to resist motion) is the coefficient of friction times the normal force. So it's basically how much of the normal force is actually working to keep the mass stationary. Anything with a non-zero coefficient isn't slippery, but resists movement to some degree, so it'll help you ...
by TychoMaudd
Tue Jun 19, 2012 11:03 pm UTC
Forum: Science
Topic: The answer! The answer! My internets for the answer!
Replies: 19
Views: 4816

Re: The answer! The answer! My internets for the answer!

I was solving this for fun (having not taken physics like this for over 8 years) and I noticed something interesting to me. The force needed to hold it stationary varies depending on the angle(though I suppose that should be obvious in hindsight)! Is it correct that the minimum force needed (~268N) ...
by TychoMaudd
Tue Jun 19, 2012 11:04 am UTC
Forum: Science
Topic: Worst thing you've seen in a lab
Replies: 256
Views: 233212

Re: Worst thing you've seen in a lab

Then, in the physics lab course in the following semester, we had to measure the adiabatic exponent of carbon dioxide. We hat one bottle of CO 2 and two groups carrying out several measurements in a row, so we just left the bottle open and hung the pipe out of the window instead of getting up and t...
by TychoMaudd
Fri Jun 01, 2012 1:52 am UTC
Forum: Science
Topic: Help with Organic Chemistry
Replies: 11
Views: 5266

Re: (Org. Chem. Homework) Determining SN1 vs. SN2 reaction.

c) MeO-/MeOH vs MeO-/DMSO" For (a), I put NaSH, because H2S is more electronegative. Also, NaSH is a stronger base, which tends to mean it is a stronger nucleophile, right? For (b), I put NaOH, with the same reasoning. I'm not entirely sure what is meant by (c). Thank you once again. For c) it...
by TychoMaudd
Mon Apr 23, 2012 10:27 pm UTC
Forum: Science
Topic: Representing chemical formulas as a single number
Replies: 73
Views: 11176

Re: Representing chemical formulas as a single number

Whilst we're on this tangent, in case scratch does take your excellent advice and investigate Euler's identity, it should be a "+" not a "-" (or the equals sign can be moved instead). Doh! I knew there was a problem posting half drunk after working a 12hr shift. It's fixed now, ...
by TychoMaudd
Sun Apr 22, 2012 8:53 pm UTC
Forum: Science
Topic: Representing chemical formulas as a single number
Replies: 73
Views: 11176

Re: Representing chemical formulas as a single number

You are right that I need to learn more chemistry. Not all theories can make predictions. My theory is more of a descriptive theory that describes certain sets of numbers in a different way than just writing the numbers down. If you can't make predictions then it is not a theory, just a hypothesis....
by TychoMaudd
Sun Apr 22, 2012 12:41 pm UTC
Forum: Science
Topic: Representing chemical formulas as a single number
Replies: 73
Views: 11176

Re: Representing chemical formulas as a single number

I see nothing wrong with saying 22 and 7 are special because 22/7 is approximately equal to pi. It raises the question as to why those numbers approximate pi while most other numbers don't. I am sure some mathematician has wondered this and I wouldn't be surprised if the answer to this was already ...
by TychoMaudd
Tue Apr 17, 2012 6:42 am UTC
Forum: Science
Topic: Representing chemical formulas as a single number
Replies: 73
Views: 11176

Re: Representing chemical formulas as a single number

scratch123, instead of spending all this time trying to analyse molecules and atoms with an arbitrary system that you try to adjust to fit things already known, why not take a look at mathematical descriptions that already have been shown to represent them very well? Quantum theory provides a very g...
by TychoMaudd
Wed Apr 11, 2012 2:39 pm UTC
Forum: Science
Topic: Representing chemical formulas as a single number
Replies: 73
Views: 11176

Re: Representing chemical formulas as a single number

[i I will settle for the same method producing equivalent results for other addictive drugs but I would be even more impressed if its application were to be shown to be broader by testing other compounds as gmalivuk suggests or maybe even some inorganic compounds/complexes. Try it with methamphetami...

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