rthmjohn

Hmm... I'm not sure I follow this ryguy. Atoms without nuclei? Isn't that a big oxymoron? I wonder if he even understands what he posted...? Just read the article. Doesn't sound like the author completely understands the subject matter either. It looks like we may need an actual physicist or physics professor to explain these "mesoscopic semiconductors".

Let's see... I plan to use the two flower pot method with some Cr2O3 and Al. The reaction will take place within the suspended stacked flower pots and fall through the holes into a pail of sand. The Chromium metal product will have quite a few impurities aside from alumina. i.e. sand and the MgO from the Mg fuse.

The wording of this problem is quite strange. I attempted the problem and gave up half way through. I think I simply miscalculated when when using the PV over nT = PV over nT. Here's the problem word for word: An empty glass container has a mass of 658.57 g. It has a mass of 659.45 g after it has been filled with nitrogen gas at a pressure of 790. torr and a temperature of 15 degrees C. when the container is evacuated and refilled with a certain element (A) at a pressure of 745 torr and a temperature of 26 degree C, it has a mass of 660.6 g. Compound B, a gaseous organic compound that consists of 85.6% carbon and 14.4% hydrogen by mass, is placed in a stainless steel vessel (10.68 L) with excess oxygen gas. The vessel is placed in a constant-temperature bath at 22 degrees C. The pressure in the vessel is 11.98 atm. In the bottom of the vessel is a container that is packed with Ascarite and a dessicant. Ascarite is asbestos impregnated with sodium hydroxide; it quantitatively absorbs carbon dioxide: The dessicant is anhydrous magnesium perchlorate, which quantitatively absorbs the water produced by the combustion reaction as well as the water produced by the above reaction. Neither the Ascarite nor the desiccant react with the compound B or oxygen. The total mass of the container with the Ascarite and desiccant is 765.3 g. The reaction is initiated by a spark. The pressure immediately rises, then begins to decrease, and finally reaches a steady value of 6.02 atm. The stainless steel vessel is carefully opened, and the mass of the container inside the vessel is found to be 846.7 g. A and B react quantitatively in a 1:1 mole ratio to form one mole of the single product, gas C. a. How many grams of C will be produced if 10.0 L of A and 8.6 L of B (each at STP) are reacted by a opening a stopcock connecting the two samples? b. What will be the total pressure in the system? Some scholar at Penn State wrote this silly problem and named it appropriately a "Marathon Problem". Do you think you could help?

These sites should work for your purposes: http://www.arborsci.com/CoolStuff/cool4.htm#calorie http://bioweb.usc.edu/courses/2004-fall/documents/bisc150-lab_burningcal.pdf Also, check out Home Science Tools. They've got a site and they sell some nice calorimeters too. I think they might have something you could use.

Any idea of how I could do that?

I was planning on obtaining some metal samples by extracting them from exotic thermite reactions (ie. vanadium, chromium, nickel). Unfortunately, there really isn't a simple way to prevent the aluminum oxide from entering the molten metal during the reaction. I was wondering if anyone could help me devise a scheme that would allow for minimal aluminum oxide impurities in the metal.

If you can't make quartz then can you buy it? I mean, can you buy it at any local store? I need some for grinding media.

Unfortunately, the magnesium nitrate IS hydrated, and even worse, its granular making it relatively unreactive. I mixed some with some powdered sugar and heated it. It gave off some sparks and gas, but nothing like KNO3. I'll try it again after I grind some of the magnesium nitrate. btw... for charcoal, could I just grind some Kingsford barbecue coals? and does the reaction yield mainly oxygen and nitrogen dioxide?

I recently got this bottle of granulated magnesium nitrate. I was just wondering if it behaves similarly to ammonium nitrate or potassium nitrate, ie. mixing it with sugar or aluminum and releasing immense volumes of gas?

Like I said, the NaCl in creases the ionic character of the water. Glycerol and soap both have an affinity for water, which is polar but not ionic. This allows glycerol, which is pretty much non-polar, to mix with the water along with the soap. You usually don't want glycerol in your soap, however, so you add the salt to separate the two. By increasing the ionic character of the water, the non-polar glycerol will have less affinity for it and will then be driven away from the ionic layer. The salt also removes water from any solvated glycerol which then forms a layer of high purity glycerol beneath a layer of salt water and soap, which, at this point, still contains many impurities.

But what about metals whose nuclei are in regular arrays and whose electrons form a "sea" around them? Is this an example of ionic bonding? Does van der waals forces explain how the molecules in a clay pot or a wine glass are held together?

The NaCl "salts out" the glycerine in crude soap leaving behing hard soap at the surface of the water. I believe that NaCl increases the ionic character of water which drives the dense non-polar glycerine molecules to the bottom of the water. The soap molecules, being polar and less dense, will then float to the surface for extraction. And no, I don't believe that the K+ or Na+ cations dissociated in water though the soap molecule itself is soluble in water.

This may sound kind of dumb, but what exactly holds things together? I know that in ionic compounds like carbonates, the ionic bonds keep the individual ions in a regular formation and when you break a block of NaCl, for example, in half you are simply breaking the ionic bonds. But what about things that aren't ionic? When you tear a piece of paper, what exactly is happening? Why can't you "put it back together" so to speak? What about plastics? When you stretch them to the point that that they rip or break, what is happening at the molecular level? What was holding the molecules together in the first place? And metals... when you have, say, a sheet of copper what is holding the atoms together. Are the atoms turned to cations with their electrons acting as a "glue." What happens at the atomic level when you weld to pieces of metal together and why isn't it possible to simply put them together like puzzle pieces? Sorry if I sound stupid, but I really am clueless as to how these things happen.

I can't say I completely agree with you. Iron itself is one of the weaker reducing agents and because of this it would seem likely that the intense heat of a thermite reaction is the only thing would allow it to react faster with water. I do believe, however, that the majority of the explosion is caused by the instant phase change of water from liquid to gas and not by H_2 reacting with O_2.

I thought that the transfer of electrons was only involved in redox reactions? Is there electon transfer in replacement (metathesis/neutralization) reactions? ie HCl + NaOH --> NaCl

Where would I get quartz and what does it look like?

Stupid on my part but hey...

Then I will use chrome plated steel or quartz. They're supposed to be great on hard materials. btw... YT, is that you in your new avatar? Were you the man in the old one?

Does reaction enthalpy have anything to do with how hot a substance gets? Does thermite burn hotter than acetylene?

Various lab chems and pyrotechnic ingredients can be found for auction on Ebay, which uses paypal. Really get a good understanding of lab safety and balancing equations before you start doing advanced experiments. Remember, many experiments can put your life at risk!

You know how you can twist a closed water bottle until enough pressure builds up shooting the cap far far away? Why is it that vapor comes out of the bottle? At first I assumed that increase in pressure would lower boiling point of the water, but in fact, it raises it and therefore this would not be the cause of the vapor. What is it?

should i use ceramic or chrome plated steel?

400 mesh is REALLY good. Days is pretty standard for most applications. When you said AGES I thought you meant like a week or so... United Nuclear sells this really nice ball mill for 70 bucks with lead media. I think I'll just use this to make my powdered aluminum from now on.

Exactly how long are we talking? Is the powder finer than simply filing a block of metal. I ground up some aluminum foil in a blender into tiny little bits... would it take long to mill this?

I think permanganates are used as industrial bleaches, not for your laundry. I don't think that H2SO4 will react with (COOH)2 because two acids will generally not react with each other. Sulfuric acid, however, does dehydrate many organic compounds. Especially sugars... just be sure to mix sugar and sulfuric acid OUTDOORS