hermanntrude

One answer I had on a paper in the chemistry exams I had to mark: the question showed a diagram of an electron configuration for nitrogen which contained a hund's rule violation. The question said "state why the following diagram represents an excited state for nitrogen". The answer was this: "because the nitrogen knows it's nearly Christmas."

i'm concerned about the black duct tape. It will absorb the heat, you're right, but why do you want it to be absorbed? surely you want it to be NOT absorbed. You want the heat to stay in the water. As was stated previously the most important thing is to prevent covection. Perhaps that can be done by ensuring there's no air inside?

genecks, you are correct, the process is very dangerous, and yes a down's cell is the normal method on the industrial scale. We have no objection to discussion of the way it is done, what we don't like is people who think they can do it by a method they invented themselves using a 9V battery and some salt from the kitchen. people like that are not scientists and can cause themselves and others serious harm.

this periodic table is very nice... lots of information provided. thanks for the info :0)

that synthesis seems to have worked but as you can see it's extremely dangerous. Anyone reading this thread should think LONG and HARD before attempting to recreate the reaction. Note that the guy who did the reaction was badly hurt and could easily have been blinded or permanently scarred. Even without the extremely silly idea of pouring water onto hot sodium, the rest of the reaction could use a bit more attention to safety. To be honest i'm not totally comfortable with this link being on our site for the safety of some of our more confident and less-skilled members.

pretty lousy synthesis if you can't purify the sodium... anyway, what proof do you have that you/they made sodium? it reacts with water? so would hot powdered magnesium... so would a lot of things. I'm not saying you/they didn't make sodium... i'm saying you/they haven't proven it, and the burden of proof is on you or them. I also have concerns about your reaction vessel... what was the pan made of? how can you be sure it wasn't involved in the reaction?

you mentioned you could smell the NO2, which suggests that either you weren't using a fume hood or your fume hood isn't good enough, either way, not smart. Don't mess with that stuff, it can easily lead to pulmonary oedema.

you should be careful with that one. it's an antique

I used to know a forum-goer called SCB... it stood for stone cold bitch... that's not you, i'm guessing. she would have made more of an entrance... she was a dominatrix

We frequently get amateur chemists posting here thinking they have found a way to make themselves some sodium, which they see as incredibly exciting because it reacts with water. Most of these methods involve electrolysis. Let me explain, once and for all why this idea is wrong and foolish: 1) The reduction potential of sodium is very negative. This means that it likes to be Na+ and doesn't like to be Na at all. However, water has a much smaller reduction potential, and will easily be reduced to give hydrogen gas and hydroxide ions. The difference between the reduction potentials is so enormous that you will NEVER make sodium by reducing a sodium salt in water. You do however have a chance of making some chlorine at the other end if you decide to use sodium chloride. If you do this, you'll be making a very toxic gas which will burn your lungs in nasty ways. Be careful! A side-point to aqueous electrolysis should be bloody obvious to people but it isn't. That is, that if you DID somehow miraculously manage to reduce sodium onto your cathode (perhaps you're Jesus), then it would immediately react with the water to make sodium hydroxide again, spitting and flames inclusive. 2) There is another method for making sodium and at least this one is actually possible. It is the electrolysis of molten sodium chloride. The trouble here is that while this is fairly easy to do on an industrial scale in specially built vessels, it's very difficult to do on a smaller scale, not to mention extremely dangerous. Molten sodium chloride is not pleasant, and it's very difficult to get to those kinds of temperatures. Sodium hydroxide was another suggestion I read on the forums, and while it certainly has a lower melting point, we're talking about a strong base here... do you REALLY want a molten puddle of fuming, spitting sodium hydroxide in front of you? REALLY? No. You don't. 3) Just because you can write and balance an equation it doesn't mean it will happen. The reasons behind what reactions will "go" and what reactions won't are quite detailed and beyond the scope of this thread. However, in general, things which are considered unstable (like sodium) are difficult to make (they require less stable things in the first place, or giant amounts of energy). So, NO, you can't make sodium by doing a simple displacement reaction or a precipitation reaction. So all-in-all the net result of the above is NO! You CAN'T make sodium! The above also applies to the other alkali metals

buy some chalk

welcome to the forum, little miss clever. If you are a proper nerd, have aspberger's syndrome, OCD or are just really pedantic, you'll probably have a ball here.

I like it. From a teacher's point of view the IUPAC PT is a bit dodgy, since we talk about periodic trends and the PT's ability to describe the electron configuration of any element, but there are exceptions and confusing rule-additions as you go further down the table, and the f-block is almost never seen where it should be. The new one is simpler and I think many students would understand it better and quicker than the IUPAC one. I dont think its necessary to put it inside a tetrahedron, though, although it's interesting.

question about the ADOMAH table: on the website it states that the spd and f blocks represent equally spaces slices of a tetrahedron. Does the g-block fit into the tetrahedron? if it does, is that a coincidence or because of some equation which describes the relationship between the sizes of the sub-shells as being equivalent to the sizes of slices of a tetrahedron?

I once wrote out a version of the periodic table with the f-block in it's correct position. I made a mistake in placing Sc and Y, though. Despite that it taught me an awful lot about what the periodic table really shows and how. If I find it, perhaps i'll scan it in.

you realise of course that the US spellings are now becoming (in most cases, have already become) the standard IUPAC spellings. I was forced to change every incidence of "sulphur" into "sulfur" when i submitted my PhD. I found it very upsetting.

the molecule NH4OH does not exist in aqueous solution. It is entirely dissociated into NH4+ and OH- It's kind of semantics really but in this case the ionic attraction is intermolecular rather than intra molecular since the two ions are both molecular but not part of the same molecule. However, it's traditional not to refer to ionic bonds as intermolecular, since they're actually a bond, even when in the temporary state we find in a solution of an ionic compound. Hydrogen bonding is also in there along with london dispersive forces. Hydrogen bonding is of course the strongest by far. You could say that there are dipole-dipole interactions but in fact that's what the hydrogen bond is. it's just a REALLY strong dipole-dipole interaction.

nifty stuff. well done. Also, the RSC have a font, which is useful when word processing with chemistry. link to RSC font

hello all My name's Hermann. I'm a PhD in nanomaterials, recently finished postdoc-ing in canada and the UK, and i've got myself a permanant job in newfoundland (canada), working as a chemistry instructor. I've started developing a bunch of demonstrations for my students and ran across this forum during my searches on the oscillating reactions, which I don't have any malonic acid for :0( I might try it with citric acid....