CaptainPanic

I know of examples of cheap, clean technology that has been on a shelf for a year, maybe two now... it's not patented, and anyone can use it. http://www.tudelft.nl/live/pagina.jsp?id=29e95a1f-2887-4201-a810-d31e8234ca84〈=en Does anyone use it? No. Why not, you think? Well, anyone going into production of solar boilers is going to make a mistake. Competition will learn from the mistake, and will make a better solar boiler. Nobody wants to be the first! And as soon as anyone actually finds out how to make a good product (overcoming startup problems), the Chinese will step in, and do it twice as cheap. Many companies want to have a technology, but they prefer to have a patent to protect their interests. But I do agree that it's criminal that useful technology is locked up behind a patent! If you buy a patent, it should be mandatory that you use it!!

Shouldn't you also know the pH of the wine in case of CO2 solubility?? When CO2 dissolves into water, it forms a (weak) acid: CO2 + H2O --> H2CO3 This weak acid can then dissociate to bicarbonate: H2CO3 --> H+ + HCO3- or even carbonate: H2CO3 --> 2 H+ + CO3(2-) If the pH is high (a basic solution), almost all the H2CO3 will dissociate and form a carbonate. This means that all CO2 reacts away. This then means that more CO2 can dissolve. The opposite is also true: if you add an acid to a carbonate solution, it will form bubbles of CO2. (The partial pressure of CO2 increases, but you don't need to add any CO2 to the system... it was there already). Calculating the equilibrium at a certain pH is a bit of a pain in the butt. It's a system with three equilibrium equations (for the two reactions and the dissolving of the CO2). You'll need the acid/base constants of the two acid/base reactions (to carbonate and bicarbonate) and Henry's constant for CO2. But, let us assume for now that the 3.92 g/l is actual CO2, and not (bi)carbonate. If all what I just explained has been solved already, and we know that (bi)carbonates are not in the 3.92 g/l. Then the use of Henry's law (see: previous post) is correct.

Sound = vibrations. Plants need CO2 from air to grow. More CO2 can mean more growing (in some cases, like in greenhouses, CO2 can be a limiting factor for growth, it is not always the case). If the mass transfer is the problem, then plants would benefit from wind. But also sound could create a mixing of air on a small level. It could perhaps break the small stagnant layer of air around leaves. This could (slightly) improve the take up of CO2, and therefore the growth of plants. I did not read this, I just made it up myself... but it's not so far fetched, is it?

Right now there is absolutely no point in making a fuel from electricity... and there will be no point in doing that until all electricity is generated sustainably. At the moment, the scheme goes something like this: Fuels --> electricity This means that there is no reason to find a solution for the problem: electricity --> fuels. but it's a fun thought experiment while we're working towards clean electricity from nuclear power. And sometimes science is just that: fun

I thought that the correct question is: "What is the color of the car?"

So, biomass causes massive deforestation which actually adds a lot of CO2 to the atmosphere because the forests are burned. Windpower is bad because radar doesn't work, the blades cut birds in half, and wind turbines are generally considered ugly. Solar cells are too expensive. Nuclear power is causing pollution that we cannot clean. Wave power and tidal power are bad for fishery, and still too expensive. Hydro power is ok, but there are not enough rivers in the world. That may all be true, but we should compare these arguments against the other option: Fossil fuels. We're digging for tar sands in Canada and digging for coal, oil and gas all over the world... And are the fossil fuels the best option? I'm not so sure. I think that too many people are too good at finding problems with sustainable energy. These problems are then presented in a stand alone reasoning, where the arguments against the sustainable energy are not weighted against the other alternative: fossil fuels. So what that wind power interferes with radar? The choice is: "Fossil fuels and rader" vs. "Wind power and also radar, but less". I go for option 2.

In an interesting article to which I cannot link (can't find it anymore) some economists claimed that the ban on smoking is costing a lot of money. The reasoning goes something like this: Smokers get lung cancer, which costs money (medical care). Then they die. Non-smokers get old, which costs a lot more money. They are receiving medical care and other care for elderly people for a very long time. Just thought that this is interesting because a lot of people are saying that the expensive cigarettes are a way to get more tax. A smoking ban might actually cost the state some money. (That all depends on the medical system you have of course).

You have answered your own questions when you stated that the Tachyons are hypothetical. (Hypothetical means that no evidence was found yet - but some people expect it is possible). I generally associate the word "Tachyons" with Star Trek. Tachyon-beams are the default solution for any problem in Star Trek, The Next Generation.

Why is it that people who don't know anything about chemistry always want to do dangerous things? Oh wait, I know, it's because they don't know anything about chemistry. Quoting from a Material Safety Data Sheet of Nitrocellulose: Stability: Very flammable. May explode or ignite without warning when dry. First convince me that you are working safely, then I might consider to explain how to make the calculations. Science is cool, but safety comes first.

Although your comment was not targeted at me, thanks for pointing out that signatures exist.

Nice pictures are welcome, but it's even better if we know what we're looking at! I have no pictures of myself, so I'll just post a link to a site with lots of colourful stuff. Not sure if it's wallpaper quality http://www-vis.lbl.gov/Vignettes/ - there are some pics of ball-and-stick models of proteins. And if you look for pictures, here's a good tool: http://dearcomputer.nl/gir/ - It uses Google images, but goes straight to the full size versions. Also, it lets you select the preferred size of the pictures (I advise: xxlarge here)

One of the reasons that it's not listed is that these bonds are ion-ion bonds. The reaction involves an electron moving from the Na to the H. This means that not only do you break a bond, and form a bond, you also remove an electron, and add an electron. The half reactions are: 2 Na --> 2 Na+ + 2e- 2H2O + 2e- --> 2OH- + H2 The bond energy you're looking for is called "lattice energy", and they are generally not listed in the more common books of chemistry. You'll need a book on inorganic chemistry that focuses on solids. Wikipedia has an article about it: http://en.wikipedia.org/wiki/Lattice_energy, but it's not wiki's best. Hope this was useful. p.s. we're now way beyond the first question as posted by ChemSiddiqui. Guess that's ok. (It's even fun).

Ok, so my understanding of hydrazine (N2H4) is that it is an unstable explosive with a flash point of 52 deg C. My understanding of things falling back to earth is that they heat up... heat up enough to become shooting stars. Now, really, I should believe that this hydrazine is actually gonna rain down on me? Come on! It will react, and form hydrogen and nitrogen. The hydrogen will also burn up and form water. It's not the toxicity of their hydrazine that the US military is afraid of. (And if such things really concerned them, they wouldn't be putting nuclear reactors in orbit). It's just a matter of preventing military equipment falling into the wrong hands. The rest of the story is to make it look like the US are doing a good thing (after they criticized the Chinese for doing the same to a weather satellite). And I also don't believe that the US military is concerned about space debris. They don't seem to do long-term thinking... or any kind of thinking at all.

A fuel cell is nothing but a complicated system of a battery + electric engine. There is no Carnot cycle in the fuel cell + electric engine. Theoretically, it can exceed the Carnot efficiency. Whether it is done in practice, I don't know, but I bet it's a hell of a job to beat the 70% efficiency that was mentioned earlier. Thinking theoretically (everything is easier on paper), I don't see why you could not reach a very high efficiency, if you're somehow able to overcome all internal friction problems (this includes friction in the engine, and also diffusion problems, i.e. mass transfer, in the fuel cell). Turning hydrocarbons into hydrogen can also be done. One way of maximizing the hydrogen output is to "water gas shift": H2O + CO --> H2 + CO2. This makes sure that you oxidize all carbon as much as possible, and leave all hydrogen unoxidized. Of course, you need to gasify the fossil fuel first (gasify = heat up with no oxygen present, basically turning everything into gas molecules, mostly CO and H2 - definitely in the don't try this at home category, CO is highly toxic and it's all explosive). However, the water gas shift reaction is an equilibrium reaction, and it does not go to 100% H2 + CO2. This means you need a separation and a recycle (costs energy). The fuel cell does produce a lot of heat, and to overcome the internal diffusion problems, they are heated to high temperatures. This costs energy. And finally, electric engines are efficient, but not 100%.

Eeh, yeah. That was not my best reply on this forum So, the heat of combustion is easy to measure. (You just burn something, and measure the change in temperature). To measure the enthalpy of formation, you need to form some compound from its elements, that experiment is a lot more difficult or even impossible. Does that answer the question? Here's some more info: (Heat of combustion) = -(heat of formation of your compound) + (heat of formation of combustion products: often just H2O, CO2) Or: (heat of formation of your compound) = -(Heat of combustion) + (heat of formation of combustion products: often just H2O, CO2) Make sure you get the minuses at the right place there! If something creates heat when it's burned, the heat of combustion is negative! The trick is: 1. The heat of formation of the combustion products is known (wikipedia or a book). dHf(CO2) = -3.935E5 J/mol dHf(H2O, liquid) = -2.86E5 J/mol 2. The heat of combusion of your chemical is measured. 3. You can now calculate the heat of formation of that chemical. Hope this answers the question a bit better. (I was in a bit of a rush yesterday).

Eeh... Sorry if this sounds rude, but your question is very vague. It sounds like you ask this forum to give you: 1. a topic for a presentation 2. background information on the topic 3. to keep it simple for you But I believe you have to make the presentation, not the other forum visitors. But you're right about the respiratory system: it is dependent on oxygen. "Not too much, not too little," as the breathing people say! You'll see that the better your question, the better the answer. For this moment, all I can advise is: google and wikipedia.

For the less common chemicals, it is normal that in literature the heat of combustion is listed. If you need the heat of formation, you have to calculate it from the heat of combustion.

I'm glad to hear you're still motivated! It's true about the school grades, nobody ever asked about those again after I finished (so: it's the same in the Netherlands as in the US). First it seemed the most important thing in the world, less than 3 months later, I had all but forgotten about those grades. It's a bit strange actually, come to think of it. Funny is that right now I'm working, and the same goes for my university grades... work experience seems the thing that really counts (and since you're only 17, really, there is no way that you have screwed up chances for work experience yet).

My story also goes for other "dead ends" in the water cycle on earth. Inland lakes and seas that have no exit point to open sea become salty too (if you give it enough time). You can think of the Dead Sea in Israel, and lake Aral and the Caspian Sea in Asia. Again, this is because the rivers bring small amounts of salt to the sea, the water evaporates, and the salts stay. Interestingly, the Dead Sea contains very high amounts of salts, and salts different from other seas. It has a large potash industry on its shores (potash is basically potassium carbonate (K2CO3) and other potassium salts, even nitrate). The oceans don't contain lots of carbonates. http://en.wikipedia.org/wiki/Potash http://en.wikipedia.org/wiki/Dead_Sea

You can see the sea and ocean as the end-point of every drop of water (in the liquid form). Water rains down on some land, goes to a river and then to sea. When it falls on the land, salts dissolve in the water, in very very small amounts, but still, a little salt always dissolves. This water then flows to the sea. So, all the salt ends up in the sea... The water can evaporate, and rain down again, but the salt cannot evaporate (have you ever seen a boiling salt?). There are several salts that are washed down to sea like that... As mentioned before, Sodium Chloride is the most common in the sea... So why not potassium nirtate (a fertilizer)? After all, potassium nitrate is common on land. The reason is that it's a fertilizer, and the rivers and the sea are also full of plants. These also consume the fertilizer salts. So, my conclusion is that the sea is salt because the salt is washed down to the sea, and cannot evaporate and is not consumed.

I don't encourage anyone to breathe hydrogen but I do think that the inside of the lungs is one of the least likely places for sparks or fire to occur. The danger obviously comes when you breathe out an explosive mixture (with half of it still in your lungs)... if anything happens that was not planned the flame will propagate so fast that it will burn you inside and outside. Burning your lungs sounds very lethal to me. I would think that outside is a better option for your experiment, because of good ventilation. Still, cars are very likely to carry a charge, and any object theoretically can unless you're 100% certain it's properly grounded. Static electricity can kill you if you are playing with hydrogen.

I'm definitely no expert on this, but I heard that thunderstorms and electric fields have an effect on the (pleasant) smell in a park or forest. I've heard that is because small aerosols are liberated which have a smell when subjected to this electric field. I can think of other reasons why this smell is associated with summer's rain, that have nothing to do with electric fields... so before writing this down in your project, please doublecheck. Good luck.

Think of white colored fireworks. Like Observer said: Magnesium burns white. So does titanium.

A lot of GMO's (Genetically modified organisms) are simply single cell organisms. These only grow in labs (or factories, which in a way are just large labs). Many types of yeast for example are GMO. These will be used to push towards a higher ethanol production from all kinds of feedstock to bioethanol plants. It enables us to use for example xylose as feedstock for ethanol. Other microorganisms are grown to produce enzymes for us. This is a growing industry, which (I think) will have many benefits. Just wanted to give two positive points of GMO's.

In a very, very general way, an acid is a combination of any compound and hydrogen where the hydrogen can come off as a proton when it is dissolved in water. My guess is that your best way to make an acid is to look up a number of synthesis routes, and study those. Some strong acids are: H2SO4, HNO3, HCl. These all come from gases (see: wikipedia for synthesis). Of those 3, only HCl needs hydrogen in its production: H2 + Cl2 --> 2 HCl (don't try this at home if you're no expert) I have never heard of an organic acid that needs hydrogen in its synthesis. Organic acids are very oxidized (they contain a relatively large amount of oxygen atoms), and hydrogen will actually reduce them. Like: Formic acid + hydrogen --> methanol + water HCOOH + 2H2 --> CH4O + H2O Acids from crystals... Any crystal with NH4 in it is already an acid, so that's not what you meant. Eeeh... Ok, sorry, no suggestions at the moment. I just realize that all acids I mentioned can be made from minerals as well. (Sulfuric acid is the acid form of a sulphate, and sulphate is a compound in minerals). Still, you don't need hydrogen (not in its gaseous form at least) to make the acids.