John Cuthber

This stuff was meant to be the oxidised form. It hasn't oxidised. Adding steel wool would turn it into something else. It has, as was pointed out earlier, picked up watter (possibly lost HCl too) and hydrolysed. In solution FeCl3 is greenish yellow (usually with a brown sludge at the bottom) This is the colour of the FeCl4- ion.

It's a matter of deffinition I think. The "poisons" are nuclei with high netron capture cross sections. They do that whether they are dissolved inlight or heavy water or, for that matter , if they are in the gas phase or anything else. On the other hand, because the capture cross section for heavy water is less than that for light water, you can get away with a slightly higher concentration of "poisons" in heavy water.

Carbon disulphide is nearly spontaneously inflammabe, it's neurotoxic and it smells like a rank fart. Surely there's some other solvent you could use?

2 days later and no comment from the OP. OK so I'm paranoid, but; the evidence that this is not a "drive-by trolling" is what?

What did you make the sodium from?

Claim that science is your faith and that they are depriving you of the right to worship here.

I'll be honest, I called him "that guy" because I couldn't be bothered to cut and paste his name, and I can't spell. It's a comment on my laziness, not his standing.

Sorry, but that's going to be quite difficult, even with a good pump etc. Unfortunately, solids generally are not very volatile. What are you making? could you use something that can be dissolved away, rather than sublimed?

I think (though I'm not sure) that he is trying to refute the idea that the law of multiple proportions is stronge evidence for atoms. Hydrogen forms 2 oxides- H2O and H2O2 For a given mass of hydrogen the mass of oxygen combined with it in these 2 compounds is in a simple proportion. 1 to 2. Similarly for iron there are 2 chlorides, for the same mass of iron you can get two different chlorides, one with 2/3 times as much chlorine as the other. Again, it's a simple proportion. These simple ratios make sense for compounds made from atoms, but if there were no atoms to do the "counting" how would the numbers "know" how to come out as simple ratios? To me that seems like strong evidence that there are atoms, and it's among the first "scientific" evidence of atoms that was available. Now what this guy is saying is that if you have 2 compounds of some sort and you measure the proprtion of, for example chlorine, and they come out as 123456789 to 234567891 then you can still say that's a "simple" pair of numbers- in fact, for any ratio, there will be a pair of numbers that give "close enough" to the right ratio so you could claim that the compound is made from 123465789 chlorines in one case and 234567891 chlorines in the other. Of course some of us might say that 2:3 and 1:2 are a lot more sensible. However he has got something of a point because there are non stoiciometric compounds where the ratios are not exact numbers, for example FeO practically never has exactly the same number of oxygens as iron atoms.

What they found (just as an example- I don't have the real numbers) is that while they expected a shift of 0.9 they found a shift that was "too small to see". Then the calculated how small a shift they would be able to see and found that calculation gave 0.01 So they know that any shift is less than 0.01 and that they cannot rule out the idea that it might be zero. Someone could always say "the shift was 0.001" but there's no way to check that without a better experiment. It doesn't matter- if I have a theory that says that there are less than ten bananas in my kitchen and someone finds there are lots, but stops counting after they find the first 20, they have still disproved the theory even though they don't have an exact measurement of the number of bananas. "I would think that the search for nothing should return exactly that. 0 right on the money each and every time." why? If I weigh a rock and send it to a friend and he weighs it the difference in weight (ignoring a few oddities) should be exactly zero- but would you expect it to be. That would require that my balance was perfectly accurate and so was his. Then we come back to those oddities. If he is at a different latitude then his measurement will differ from mine because of the earth's spin. If he's at a different height above sea level that will also have an effect. I can try measuring those factors and try to compensate for them, but I can't do that perfectly so I expect to get some value for the difference in weights that is near zero, but not exactly zero.

I wondered about that, but I think the fact that nitric acid is a rather stronger acid would mess things up.

In order to carry anything like that load you would need to put on a lot of muscle- so you would a lot weigh more. It's quite possible that you would be able to jump less effectively.

Looks like a plug for a website.

I don't know where you are, but in the EU it's a requirement that the manufacturer/ supplier can give you a msds. Where did you get the stuff from and can they help you?

"If you freeze your solution, you will effectively purify it to nearly 100% because water freezes at 0 degreese celcius and will be solid" No it won't. If you freeze the mixture there's every chance that you will get a eutectic mixture rather than a pure component. In any event the stuff won't freeze anywhere near 0C. Page 8 of this http://www.charis.wlc.edu/publications/symposium_spring02/hansen_a.pdf gives the phase diagram for nitric acid/water. The addition of phosphoric acid would make it more complicated still. Adding a fuel like methanol to a strong oxidant like nitric acid wouldn't be a good idea and since the mixture won't freeze in ordinary weather I doubt they will have added any antifreeeze. Distillation would be the way to go but you need a still that will cope with this rather corrosive mixture and that's not going to be easy.

Frosch45, What the F*** has methanol got to do with it? I also wouldn't expect to see an insoluble solid like naphthalene in antifreeze. I don't know what menthol costs as a bulk chemical but a 1999 fine chemical catalogue lists it at about £50 per pound. Naphthalene is probably 10 times cheaper. The vapour pressure of menthol is about 1.3mmHg at 56C based on an MSDS I found, but this http://jeb.biologists.org/cgi/reprint/20/2/159.pdf gives it as 1mmHg at room temp. Naphthalene seems to have a vapour pressure of about 0.1mmHg or less at room temp. It seems odd that even for so well known a chemical as naphthalene there isn't any good data on the vapour pressure on the net.

Naphthalene and menthol fit the bill but are not really non toxic. (nothing is).

There's some sort of communication failure here. A test tube is an open container. A few inches of dilute iodine vapour aboue the liquid is going to make less difference to the pressure than going down the stairs to the next floor of the building. How could it make any difference to the melting point? Those phase diagrams ar about equilibrium conditions so the rate of loss of vapour doesn't enter into the debate. If you get I2 to about 150C at atmospheric pressure it will melt. It's very volatile under those conditions, but the liqid does exist.

There are some very blue copper complexes of copper with citrate. You wouldn't need much of an impurity to send it slightly blue.

Both. If you charge a capacitor then wait a long time and measure the voltage you will find that it's less than you charged it to. This leakage of charge can be modeled as a (large) resistance in parallel with the capacitor. The ESR limits how fast you can discharge a capacitor (neglecting stray inductance) and the leakage resistance limits how slowly you can discharge it.

Pioneer, as far as I can see you are proposing to punish (some) children for something for which they are not responsible. To me that's just plain wrong and it doesn't matter if their condition is due to nurture or nature. Once you have a group that can be identified as "in need of a good hiding" then either you have brought them up badly, thereby training them that way; or they are born that way. Smacking them for your failings or their genetic bad luck seems no better than just hitting unruly children because they make you angry- at least you can blame instinct for that.

The original post poses an interesting question. Perhaps some more data will explain it better so I'm cheating and copying some directly from Cotton and Wilkinson's advanced inorg chem. Acid strengths for acids of the form HnXOm tabulated by m-n m-n acid -log K 0 HClO 7.5 0 HBrO 8.7 0 H4GeO4 8.6 1 H3PO4 2.12 1 H3AsO4 3.5 1 H2SO3 1.9 1 HNO2 3.3 1 H2CO3 6.4 1 HClO2 1.94 2 HNO3 large negative value 2 H2SO4 large negative value 3 HClO4 very large negative value 3 HMnO4 very large negative value There's clearly something about having more oxygens attaced to the central atom that makes these stronger acids- and it's the electronegativity of oxygen that does it. There's also something about not having many hydrogens to share the "acidity" among that also contributes . That's why, as Reactive pointed out, H2CO3 should be a lot stronger than it is. It sticks out like a sore thumb. Now I think I have identified the real question here- why is H2CO3 2 or 3 orders of magnitude weaker than the acids with a comparable structure? The same book gives an answer. The usual given value for the acid strength of carbonate overlooks the fact that CO2 dissolves in water but only part of it hydrates to H2CO3. If you correct for the fact that much of what you expect to be H2CO3 is in fact CO2 in solution, you get a more sensible answer for log K of about 3.6 which is pretty much in the range you expect. Hope that helps.

Gold is perfectly immune to the effects of NaOH. I can't think of any way that gold would be oxidised to Au(III) by soap and lye as Frosch45 sugests. If anything I would expect soap to reduce Au(OH)3 to the metal. I also can't think of anything that would be in any normal soap that would affect gold. My best guess is that the "gold" isn't gold. Perhaps you should ask the supplier to explain why his "24K gold" is affected by soap.

Good question. Imagine a couple of small specks of dust an inch apart and both very brightly iluminated (perhaps by a laser). You would be able to see them provided that they scattered enough light in the direction of your eye. You would be able to point at them and estimate the distance between them. You wouldn't be able to say anything about them apart from the fact that they were bright dots (and how bright they were). If the 2 spots were close enough together they would look like just one spot. That distance is the resolution that the post above gives.

"That's not necessarily the case, nurture can be the root causes of loads of behavioural problems. Including in the very young. That classic experiment with little Albert is a case in point" True, but to some extent it doesn't matter. It's too late by the time you can tell if a child is unusually defficient in attention.