woelen

Yes, that is true, but if you start from correct half-equations and you add a linear combination of half-equations to each other, then you do not have to worry about charge balance, nor about a correct balance of elements. That 'automagically' will be correct, provided the half-equations are correct.

I have read that Wiki-letter and it is a decent piece of work. To a large extent I can agree with it, but for me (as christian) a very big question remains unanswered. As a christian, I stand somewhere in the middle, not accepting the 6000 (or 10000) year young earth view, but I also have some large problems with the theory of evolution (toe, as it is mentioned in the letter). I accept that earth is very old (around 4.3 billion years??) and also that the universe is very large and possibly infinite, and increadibly old. I also agree with the observations of the fossils and the presence of species through time. However, as a christian I also fully believe that at a certain point in time sin came into the world ("the world is fallen in sin", as some church-leaders call it). This is a central theme of christianity. If you do not accept that, then why would you even continue believing? Then Jesus' work was void and without any meaning and He would be a fool. So, I fully accept that the world is fallen in sin. Now the problem with the toe. I see no way, how this falling in sin can be unified with the current toe. If there are any other christian members of SFN over here, who accept evolution, and who really are christian and accept that the world is fallen in sin, then I would be really eager to read how they think these two things can be unified. So, for me, up to now, the answer simply is open, and I have to leave it open. There are the observations, and there is the dogma of a world, fallen in sin, and both I have to accept, but I see no theory, which fits both of these in an acceptable way.

Yes, there is, and I did some math already a few posts ago. The key to this is the Faraday number. It relates the number of Coulombs of charge to mols of electrons. 1 mol of electrons is 96485 Coulomb of charge. An electrolytic cell, which splits water in hydrogen and oxygen will take appr. 2V of voltage (redox potential plus overpotential plus resistive effects). In reality, however, it will be closer to 3V than 2V I think. Well, let's say that with this device, 100 cells can be put in series, each having 17 A of current. This is a VERY optimistic estimate, meaning that almost all energy is converted to gas and hardly any energy is converted to heat. Now, you can compute how many coulombs of charge are flowing this way per hour over all cells: currrent * number of seconds in an hour * number of cells: 17 * 3600 * 100 This means that 6.120.000 Coulombs of charge per hour are effectively used for making gas. For each molecule of H2 gas and each half molecule of O2 gas, 2 electrons need to be transferred (oxidation state of H goes from +1 to 0, and that of oxygen goes from -2 to 0). So, for one mol of hydrogen you need almost 200000 Coulomb of charge. So, in one hour you can obtain 6120000/200000 mols of hydrogen gas, this means just over 30 mols of hydrogen gas. One mol of gas has a volume of 22 .. 23 liters at normal termperatures, so you can make somewhere between 650 and 700 liters of hydrogen gas per hour (and besides that, half that amount of oxygen gas per hour). In my computation I have idealized a lot of things. In reality, I think that even 50% of this yield cannot be obtained, due to constructional problems, electrical losses, etc. I would believe the claims if they say they produce 300 liters of hydrogen gas per hour, and then still I would call it a very decent job for such a small household machine. I did not do the computations for making of HHO, because that cannot be made like this. HHO simply is non-existent at the macroscopic (time)level. So, any claims in that direction (but I'm not sure whether they claim that) is nonsense.

The general idea behind this, is that half equations can be used to derive the full equations. Half equations can be added to each other in any linear combination, but that must be done in such a way that the number of electrons at both sides is the same. In the above example, there was an error, Ag is in oxidation state +1. This makes the example more interesting though. Cu --> Cu(2+) + 2e Ag(+) + e --> Ag Now, we need to combine the equations. We can do that by adding one time the copper equation and two times the silver equation. In that way, we have equal numbers of electrons at both sides of the arrow.

No, the physics and chemistry both are not correct. With 10 resistors indeed you get appr. 2.2 Ohm effective resistance, but your current will be at mose somewhere between 3 and 4 A. This is due to the voltage drop across the cell. The cell also takes 4 to 5 volts, and the remaining voltage will be across the resistors. Look at the page, which I wrote some time ago, this explains why the cell voltage is not 0. Increasing the current by a certain factor does not increase the speed at which chlorate is formed by the same factor. You even can make the cell, such that its efficiency goes down a lot, while more currrent is sent through it. It all has to do with current density on the electrodes. As I wrote before, keep the current density below 100 mA per cm². If you really want to draw more current with your second set of resistors, then make up for a second cell, and connect that to the second set of resistors, and connect both cells to the same PSU (that certainly will power both cells without problems). What you now are doing is producing lots of hydrogen and oxygen, producing lots of heat and only making relatively low amounts of chlorate. So, make another cell and do not rise the current too much though a single cell.

As H2SO4 already mentions, the sentence alone on that website is sheer nonsense. Throw in some buzzing words, and the less-informed people give it some authority. In reality: crap, not of any use. If this really were such a breakthrough, then every household would have such a device already.

Before asking that question, first try to determine, what are the other products of this reaction. To my opinion, the answer to your question will be almost impossible. The chemistry of molybdenum is remarkably complex and I doubt whether the molybdenum blue, as you call it, is a single well-defined compound with a certain stoichiometry. The only thing, which really can be said about it, is that it contains Mo in mixed oxidation states and that it the cause of the intense color of this material (compare with prussian blue and mixed oxidation state copper(I)/copper(II)/chloride complexes). Anyways, the tin is oxidized to tin (IV) and probably will form hydrous SnO2 under the conditions of the reaction. The role of the phosphate is to form very complicated polymetallate ions, containing both phosphorous and molybdenum. Without the tin (II), a yellow compound is formed of unbelievable complex structure (which still is not yet fully determined), which contains large anionic species, which consist of phosphorus, molybdenum and oxygen. With the ammonium ions this gives a precipitate. These mixed anionic species are more sensitive to reduction than molubdenum (VI) species alone. The phosphomolybdate structure has another color, but it also enhances reactivity of molybdate (VI). Why? I don't know, and rpobably noone knows precisely. On the other hand, the formation of that yellow compound is a very sensitive test for presence of phosphate, and combined with the reduction to blue compounds, it can be made even more sensitive (but also less selective).

Indeed, currently there are chemicals databases, and they contain a few million of chemicals. But these are not publicly accessible, unfortunately. Even with inorganics, there are so many many many compouds, e.g. what to think of such a compound as potassium penta(trichlorostannato(II)) platinate (IV) . I actually have made this compound once (in solution), but it only exists in very few databases. Btw, its formula is [ce]KPt(SnCl3)5[/ce].

YT, that is why I wrote that your mileage may vary. But, it is sometimes true that adding a detergent may reduce foaming, due to interaction with other foaming agents. I would not add alcohol. That reacts with hypochlorite and chlorine and reduces the cell efficiency to 0. As long as alcohol is present, no chlorate is formed at all! Before the hypochlorite can disproportionate to chorate and chloride, the alcohol has reacted with it already. The reaction, which occurs is the so-called haloform reaction.

Are your graphite electrodes treated with some linseed oil? This is a good thing, because it makes them less vulnerable to corrosion, but it also adds more crap into the solution, most notably, forming kind of foam on the surface of the solution. This behavior can be reduced somewhat by diluting the solution a litte. E.g. add 1 part of water to 4 parts of the solution. I also read about adding a drop of a detergent to the solution. This reduces surface tension and may reduce foaming. Your mileage may vary though.

Good to see this portal. Nice idea to link through to wikipedia for more detailed info on the elements. I've bookmarked it, and probably I'll use the numbers for my own website and/or experiments.

HHO does not exist as a compound, which can be stored macroscopically, in a bottle, like a liquid, a gas, or a solid. ANY compound can be made nowadays, by arranging individual atoms. Ayoms can be placed in an inert ultra-cold matrix, and in this way, very strange compounds could be made at picogram quantities. But as soon as temperature rises, or the concentration of the strange compound becomes higher than a few pMol per liter, then the compound decomposes already. This is fundamental research, which can be quite useful. It gives insight in the chemical and physical properties of the elements around us, and who knows what interesting applications may appear in the future. In reaction mechanisms, also transient compounds may exist. Some redox reactions are working through the hydroxyl radical, which has formula HO. But this radical only has fleeting existence. It is not possible to have a bottle of hydroxyl around. This compound can be formed, but will react with anything around it in nanoseconds. So, it might well be possible that a compound HHO is formed as reaction intermediate, but also this compound will be VERY shortlived (picoseconds, femtoseconds??). From a practical point of view, HHO does not exist.

When a non-stationary current is flowing through a wire, then you will have magnetic fields, and at the same time electrical fields. The total energy flux through a small surface dN of space equals [(E×B)•e/μ]dN, here E is the electric field strength, B is the magnetic flux strength, e is the unit vector, perpendicular to the surface area dN, and μ is the permeability of the medium, through which the waves are propagating, × and • are the exterior and interior product operators for 3D vectors. Perform a google search on the words "Poynting vector" and things probably may become more clear. What this shows, is that electromagnetic power can propagate through space without the need of any wires. In your setup, with a zero-resistance wire, which is connected to an AC-current source (not voltage source!!), there will be power drain from the source, due to the radiation. For similar reasons, there will be power drain from an AC-voltage source, to which a wire is connected, without closing the circuit. This effect is negligible at 50Hz AC voltage, but it can easily be observed at 100 MHz AC voltage. I once did a very nice experiment. I made a 100 MHz oscillator with a HF-transistor and a simple capacitor/inductor circuit. This oscillator was capable of producing several 10's of mW of power output. Now I did the following experiment. At the emitter of the output transistor, I connected a small tungsten bulb (2.5V/50 mA or something like that). On the other contact of that tungsten bulb I connected a little copper wire, around 1 m length. The other end of the wire was not connected with anything. Remarkably, the little bulb started glowing. What happens is that energy is lost at the wire (radiation into space), this causes a certain current drain from the oscillator, and this current drain is sufficiently large to make the little lamp glow a little. When I touched the other end of the wire, then the little light started glowing brigher. Then I became part of the irradiating object, through which energy is sent into space.

Your question is meaningless, because HHO does not exist. Water is not split into H and O, but in H2 and O2. Splitting of water must be done electrochemically. Electrolysis of an acidic aqueous solution at least requires 1.23 volts for formation of hydrogen and oxygen, in practice a little more (due to resistive losses, and overpotential at the electrodes). So, using Faradays constant, and the current through the electrolysis cell, you can compute the minimum amount of electrical energy needed to make a mol of H2 (and half a mol of O2). If you perform the calculation, you'll find that you need at least appr. 250 kJ/mol of energy. In practice this will be higher. A very efficient cell may require 300 kJ/mol, practical cells probably will be closer to 500 kJ/mol.

For rocket fuel I would suggest you to stay to KNO3. A lot more stable and well burning at an acceptable rate. For rocketry you don't want too high burning rates. Of course, you could add a payload with some nice effect, where you could use some of your home-made KClO3, but as YT and I warned before, keep in mind that KClO3 is a notoriously sensitive and unstable chemical, which already has cost many persons limbs or more. So, feel free to experiment, but always be prepared that something can go wrong with KClO3. I myself use the KClO3 I have only for fun experiments, with some flashing, high-speed buring powders and so on, but to my opinion it is not suitable for real pyrotechnics, unless you have a lot of experience of knowledge. If you really want more about this subject, then I suggest you to read the following very interesting forums, devoted to pyro and rocketry. I did not register in them, but I regularly read them with pleasure. General pyrotechnics: http://groups.google.com/group/rec.pyrotechnics Rocketry: http://www.ukrocketry.co.uk/forum/index.php?act=idx Interesting reads....

Of course, making such a flame is not impossible. You could even make much larger flames, but making a liter of gas per second requires an enormous amount of energy. Just a small computation: At room temp. one mol of a gas takes up approximately 22.4 liters of volume. So, we need to make 0.045 mol of gas per second. For each mol of gas, two electrons are needed (H goes from oxidation state +1 to oxidation state 0). So, we need to make 0.09 mol of electrons per second. Now compared to current. 1 mol of electrons is approximately 96485 Coulomb of charge. A current of 1 A produces 1 Coulomb of charge per second. So, we need a current of 0.09*96485 A to make 0.09 mol of electrons per second. That is almost 9000 A!!! Of course, you could make a lot of cells in series, but still, making 1 liter of gas per second requires a LOT of power. This can be done on an industrial level, but certainly not at home. So, making a car, working on water and electricity, which is fully charged in let's say an hour from a simple wall-outlet, simply is not possible. Anyway, I do not believe in hydrogen-powered cars at all, where the hydrogen is from a home-setup. Maybe in the future we will have hydrogen-powered cars, but the hydrogen will not be produced at home.

This is all sheer nonsense. Electrolysis of water requires a lot of electrical energy. If you wanted a 50L tank, full of fuel, and you wanted to use water for that, then that would require 300 days of elctrolysis at a current of 10A (which is quite a lot already). Even, using 100 cells in a series-circuit, that still would take a full 3 days of electrolysis for a full tank. So, the story of 20 minutes of electrolysing, making the water into a flammable liquid is pure bullshit.

[w00t], well done job. That looks quite good. I want to give you one suggestion: Do not light such mixes with a short match. The mixes you have here are burning with a smooth flame, but I have had mixes, which reacted very unpredictably, spraying all kinds of moltens salts around. Last year, I burnt my fingers from just 50 mg of red P/KClO3 mix, "lighted" by mixing it with a little wooden stick. The stick had a length of approximately 20 cm, but that was not sufficient to protect my hand and fingers from being burnt. I must not think of having 200 mg of this mix, lighted with a short match. You can buy so-called barbeque-lighting matches (at least over here, I don't know the situation in Australia), try to find those. It is much safer.

Understanding these patters indeed is very difficult. There is some pattern, but then you need to broaden the view to other parts of the periodic table. When you look at the highest oxidation state compounds of chlorine, bromine and iodine, and you compare that to the corresponding compounds of sulphur, selenium and tellurium, then you see a similar pattern. Sulphate is the most inert of these, the selenate is hardest to make, but once you have this compound, it is less reactive than selenite. Tellurate is easier to make than selenate. The resemblance is not 100%, but there definitely is a pattern. Again, a similar pattern exists for phosphate, arsenate and antimonate, but here the pattern is much less pronounced.

Yes, that is the main point of chemistry. A shift of a single electron can make a whole lot of a difference. The properties of all chemical compounds around us are determined by the electronic configuration around the nuclei. The nuclei themselves do not interact in any way in chemical reactions and also do not contribute in any way to the physical properties, other than mass, of the chemical compounds. The molecular orbital's shape goes from fully distributed over all atoms in a purely covalent bond to fully around one atom in a purely ionic bond.

@RyanJ: Informally speaking you are right. When a compound looses energy, it moves towards a more stable form, while heat and/or light is released. On the other hand, putting energy in compounds can transform them to a less stable compound or set of compounds. @Neil9327: This is a reaction, described on my website: http://woelen.scheikunde.net/science/chem/exps/Fe+HNO3+Gimp/index.html

There are two types of extremes, when we are talking about chemical bonds. One type is the so-called covalent bond, where electrons are shared between (usually) 2 atoms. An example is Cl2. Both Cl-atoms are 'missing' one electron. Both of them 'donate' one electron and they share the two 'donated' electrons. That makes them both happy, because they now both have a full set of electrons. The other type is the so-called ionic bond, where electrons are not shared, but really transferred. An example is NaCl. Na has one surplus electron and wants to get rid of this. Chlorine wants another electron. Both elements are happy if this electron is transferred. Na gives it to Cl. Na becomes an ion Na(+) and Cl also becomes an ion Cl(-). The total compound now consists of ions in a 1 : 1 ratio. A better formula for salt hence would be Na(+)Cl(-) instead of NaCl. In the real world, however, the two extremes are quite uncommon. Cl2 and NaCl are two extremes, but most compounds, consisting of different atoms are somewhere inbetween. The atoms share electrons to some extent, but the sharing is not equal. E.g. in H2O, each H shares its single electron with an electron from an O. In this way, each H has two electrons and each O has 8 electrons in its outer shell. However, the O atom shares it a little bit more than the H-atoms, so in water, there is a slight negative charge on the O and a slight positive charge on the H, so the real structure is H(δ+)O(2δ-)H(δ+), with δ < 1, but definitely larger than 0. In general, for compounds, atoms have a charge nδ (here n is the formal oxidation state of the element, e.g. -2 for oxygen, +3 for aluminium, +2 for calcium). The closer δ is to zero, the more covalent a compound is, the closer it is to 1, the more ionic it is. Some examples: Na(δ+)Cl(δ-) : NaCl, almost purely ionic, δ very close to 1 Ca(2δ+)O(2δ-) : CaO, almost purely ionic, δ very close to 1 Cr(6δ+)O(2δ-)O(2δ-)O(2δ-) : CrO3, δ very close to 0, almost purely covalent Compounds like Fe2O3, Cr2O3 and Al2O3, MnO2 are very much inbetween. Their δ is not close to 1, but also quite far from 0. Hence, they are intermediate and one cannot call them purely covalent, but also not purely ionic. ======================================================================== In many compounds, both types of bonds occur at the same time. Inside the compound KNO3, for example we have K(δ+) and NO3(δ-), with δ very close to 1. This means that the compound KNO3 is almost purely ionic. But, inside the unit NO3(-), the atoms are bound almost purely covalently. So, we have ions K(+) and NO3(-), but NO3(-) itself can be regarded as a covalent molecule, but now with a total charge on this molecule, equal to -1. When we look at the compound HNO3, then the whole molecule can be regarded as covalent, but with a fairly large δ+ at the H-atom. In the nitrate ion, however, the electrons are not simply shared between two atoms, but the total set of electrons, available for bonding is shared over all atoms. As I stated at the beginning of this post, electrons usually are shared between two atoms, but they can be shared between more atoms. In the nitrate ions (and in fact in many other ions and molecules) this is the case. Another example of such a situation with more electrons shared by multiple atoms is benzene, where 6 electrons are shared by 6 C-atoms. This type of covalent bonds over multiple atoms is called 'delocalized bonding'.

Sensitivity of the oxo-halogenates is as follows, starting with the most sensitive, ending with the least sensitive (from a pyro point of view): bromate chlorate periodate perbromate perchlorate iodate So, iodate is the least powerful of all. Strangely, when we look at the perhalogenates alone, then indeed the periodate by far is the most sensitive. I have periodates and perchlorates, and the periodates are much more reactive than perchlorates, and also much more reactive than perbromates. Written somewhat different: bromate > chlorate >> periodate > perbromate > perchlorate > iodate Here, bromate and chlorate both are much more reactive than all the others. ========================================================== In aqueous solution the order of reactivity is somewhat different: bromate/periodate chlorate/iodate perbromate perchlorate In aqueous solution, bromate and periodate are very reactive. Chlorate and iodate are about equally reactive and perbromate and perchlorate are almost inert in aqueous solution. So, writing it somewhat different: bromate ≈ periodate > chlorate ≈ iodate >> perbromate > perchlorate Perbromate and perchlorate are much less reactive than the others in aqueous solution. I once boiled a strongly acidified solution of NaClO4 with sodium iodide, and the perchlorate was not capable of oxidizing it, not even near boiling conditions!

This is why I hate MSDS sheets. To my opinion they even can introduce additional danger, because they do not discrimiate between "some danger" and "a lot of danger". Compare the MSDS sheets of e.g. NaCl and NaOH from the same manufacturer. http://avogadro.chem.iastate.edu/MSDS/NaCl.html http://avogadro.chem.iastate.edu/MSDS/NaOH.html In both cases the MSDS states that you should use safety glasses (with side protection), gloves, protective clothing, and a NIOSH/MSHA approved air purifying dust or mist respirator. If you read such a thing about NaCl, then you can only laugh about that. Now, the same things are written for NaOH. For that chemical glasses certainly are a very good thing, and gloves also are a must. I also noticed the very acrid and biting smell of a concentrated hot solution of NaOH, so if you work with large quantities then some form of ventilation also is highly recommended. In MSDS's there only are very dangerous chemicals, extremely dangerous chemicals and ultra dangerous chemicals . That is a pity. People do not learn to discriminitate between things which are somewhat dangerous, and things which are REALLY dangerous. This can lead to accidents, because uninformed people tend to get used to dangers mentioned in documents and because there hardly is any discriminating effect, they are working easily and comfortable with fairly innocuous chemicals and the really dangerous ones. Here, YT has found another bad example of MSDS's. KClO3 and KIO3 both are called impact sensitive. We all know that KClO3/reductor mixes sometimes can go off, even when carefully mixed on a sheet of paper with a soft flexible stick. If you want a KIO3/reductor mix (same reductor) want to set off, then you might succeed if you put it on a steel plate, heat it to 400 degrees and hit it with a heavy sledge hammer. Even then, I severely doubt, whether the mix will set off. Probably you even need a very powerful primary high explosive to set off a mix of KIO3 and a reductor. Yet, the MSDS's for both warn for the same risks. YT now is somewhat overcautious with iodates, because he knows the dangers of chlorates. But the other way around is much more dangerous. Someone, used to working safely and comfortably with iodates, but unfamiliar with chlorates, may think that chlorates have the same risks (same warnings in MSDS) and at a bad day thay may have a serious accident. Also, if you study the MSDS of bromates, then things are even worse. These are even more sensitive than chlorates (I noticed personally), but the MSDS does not state that at all. From MSDS's you would conclude that bromate, iodate and chlorate all are oxidizers and very dangerous, but there is no difference at the warning level.

The combo Mg/HCl has a higher energy content than the combo Mg(2+)/H2/Cl(-). The energy is in the Mg-metal. The idea behind this is not different from the idea behind burning of combustible materials, only the amount of heat involved is a little bit less. Any chemical reaction involves heat. A reaction, which produces heat is called exothermic and a reaction which takes heat is called endothermic. An endothermic reaction usually does not occur spontaneously, one has to put effort in it. The products of such a reaction have a higher energy content than the initial materials.