[QUOTE=Cakebatyr;40002642]Every time I work with dichloromethane I lose sensation in a random finger for a few days, even when wearing gloves the whole time.[/QUOTE]
DCM goes through most gloves.
Another acid burn for the books, this time a splatter of conc. nitric acid on my finger.
Why did the bear dissolve in water?
It was polar.
Ahahaa. Ha. Anyways. What is chemistry like on a higher level? I'm doing my first year of chemistry and wondering if this is just a small part of a huge field, or is there a lot more to it than calculating concentrations and moles and whatnot?
Well, for second year chem, you start to apply your basic knowledge for more specific topics (eletrochem, thermo, organic, etc)
[QUOTE=A Noobcake;40211099]Why did the bear dissolve in water?
It was polar.
Ahahaa. Ha. Anyways. What is chemistry like on a higher level? I'm doing my first year of chemistry and wondering if this is just a small part of a huge field, or is there a lot more to it than calculating concentrations and moles and whatnot?[/QUOTE]
Of course. All science classes are general to start and become more specialized depending on your choice of major.
[QUOTE=A Noobcake;40211099]Why did the bear dissolve in water?
It was polar.
Ahahaa. Ha. Anyways. What is chemistry like on a higher level? I'm doing my first year of chemistry and wondering if this is just a small part of a huge field, or is there a lot more to it than calculating concentrations and moles and whatnot?[/QUOTE]
Well, I was in a tutorial class with people studying PhDs in a medicinal/synthetic chemistry project and they still seemed like they were learning things.
[QUOTE=A Noobcake;40211099]Why did the bear dissolve in water?
It was polar.
Ahahaa. Ha. Anyways. What is chemistry like on a higher level? I'm doing my first year of chemistry and wondering if this is just a small part of a huge field, or is there a lot more to it than calculating concentrations and moles and whatnot?[/QUOTE]
Second year you get to use machines. IR spectroscopy, UV/vis spectrophotometry, gas chromatography, etc.
And if you're lucky enough, you'll get a lab supervisor with a really thick Scottish accent to make the whole lab even better.
In other news, I've now completed 2nd year chemistry and my peers and I are waiting to see if we've been accepted to our new university.
[editline]9th April 2013[/editline]
My university only became an accredited university five years ago so we don't have the space/budget for third/fourth year labs.
Pity, the chem profs (unlike the phys/bio profs) are all extremely interesting and excited about their respective fields.
How do I know if I want sp, sp2 or sp3 hybridisation and why when you do it for methane is it sp3 despite there being 2 electrons in 2s and 2p
[img]http://www.ntu.ac.uk/images/cms51929sml.jpg[/img]
Essentially the s and p orbitals degenerate to minimize the repulsion between the bonds.
Imagine you had an elastic band, and twisted it in half so you have an infinity symbol, that is your p-orbital. Now imagine you shifted the part where the elastic crosses over itself to the end so that you almost, but not quite, have a whole loop again; that is your hybrid p-orbital. Now for a hybrid s-orbital, its kind of the reverse. Take that elastic band, form a circle with it, and put a small loop on one side of it. The sp# designation really shows how many bonds are available.
Methane is an sp3 hybridized molecule because the second tier orbitals (see the picture) rearrange themselves to minimize the steric hinderance of the hydrogen (so they don't bump into each other). sp3 is essentially synonymous with describing an atom in a molecule as "tetrahedral". sp2 happens when you have a double bond and is a trigonal planar geometry, meaning its flat. Such as O=C-H(H). sp hybridization is when you have a double/double or triple/single bond. See CO2 (O=C=O) or HCN (H-C≡N).
Be wary of relying on how many atoms are attached to the hybridized atom, because despite what it may appear, NH3 is not a trigonal planar but tetrahedral. Three H's occupy three of the four "spokes", while a lone pair occupies the fourth area leading to an sp3 designation.
[img]http://0.tqn.com/d/chemistry/1/0/S/S/1/Ammonia.jpg[/img]
Thanks
So it basically depends on how many things the central atom has to accommodate, just like the shape?
[QUOTE=Cakebatyr;40237834]
Be wary of relying on how many atoms are attached to the hybridized atom, because despite what it may appear, NH3 is not a trigonal planar but tetrahedral. Three H's occupy three of the four "spokes", while a lone pair occupies the fourth area leading to an sp3 designation.
[/QUOTE]We were taught that you can use the steric number (# of bonds + # of lone pairs) to reliably figure out the molecular geometry. I think that works pretty well.
[QUOTE=McGii;40237895]Thanks
So it basically depends on how many things the central atom has to accommodate, just like the shape?[/QUOTE]
Really the shape is determined by how many other atoms/lone pairs the central atom has to accommodate.
[editline]10th April 2013[/editline]
[QUOTE=account;40237938]We were taught that you can use the steric number (# of bonds + # of lone pairs) to reliably figure out the molecular geometry. I think that works pretty well.[/QUOTE]
Well I was more trying to say that it isn't immediately obvious that nitrogen has a lone pair when someone is just starting out with hybridizations and shapes.
The way we are told to do it and lose exam makrs for not doing is to draw a dot structure and check the formal charges first so while I wouldn't know about the lone pair right up if I'd find it out.
[img]http://i.imgur.com/L1hTCsB.jpg[/img]
Look what I made!
[sp]It doesn't actually work yet, I haven't written the usb driver for my shoebox-spectrophotometer, its just plotting a randomly generated polynomial equation[/sp]
Edit:
[t]http://i.imgur.com/8P0t600.jpg[/t]
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