encipher

If I had my own site, and wanted to add latex support to it, where would I start looking for information on adding it to my site's code (php/mysql of course)

I highly recommend the TI-89/Ti-89 Titanium for second year physics. It is much more powerful than the 83's and 84's and can do a lot more complex calculus work and algebra. Now the drawback is this: It takes some time to get used to the interface. It's so awsome you can become too reliant on the calculator. When I did AP Physics, I used it primarily to check my work,my integrals.. derivatives etc.. Also it comes in very handy when solving simutaneous equations. So I strongly recommend an 89

Electronegativity is a measure of howe much an atom attracts electrons in a chemical bond. When molecules form, electronegatity plays a role in determining the type of bond that will form. If the difference between the electronegatvity is not great, then atoms can share electrons in a covalent bond or polar covalent bond (since often bonded atoms dont have the same electronegativty, although they could, polar covalent bonds can form. Do not mix this up with the polarity of the overall molecule, because even though there could be a difference in polarity internally, the overall molecule could still be neutral) . However if there is a great difference in electronegativity, the electron will be transferred permenantly to that with the greater electronegativty, forming an IONIC bond. Polarity of the molecule refers to IMAF (intermolecular attractive forces) which can affect a lot of things such as boiling point, melting point etc.. I cannot go into detail explaining all of these IMAFs because it would be very long, you should look it up in your text. Hopefully this will help you answer the question regarding HBr and AgBr. The mass number is the number of neutrons + protons in an atom. The electron configuration of Chlorine is [Ne][MATH]3s^23p^5[/math] That means it has 7 valence electrons. In order for it to acheive a state of maximum stability, it would be 'most convenient' for it to gain an electron and completly fill the P orbital. Therefore chlorine would most likely react with anything that is able to provide that one electron. You could go into more detail regarding reactivity. This is jut a starting point for you. Hope this helps.

I just explained the use of solubility to determine net ioinic equations in my previous reply to your question. A precipitate is a solid that you cannot dissolve in a solvent. Meaning, something that is not a precipitate, will remain aqueous in a solution.

Yes, which is why i said it is a general rule. Judging from the questions 'Asian' is asking, it would seem he is still taking very basic chemistry, and I doubt anything more complex than that would appear since it was that way when i took basic chemistry for the first time. And he also stated synthesis/combination... which to my knowledge in general chemistry refers to a chemical bonding between two reactants to form a single product.

As a general rule, a synthesis reaction would have ONE product, as opposed to a single replacement which would have generally two products (depending on the replacement thats occurring)

The solubility rules for salts in water are in use all the time. Whenever two aqueous (or aqueous and solid) mix, Depending on the solubility of the products,we can determine if there will be a precipitate or not. For example: [CE]Ba(NO3)2 + Na2SO4 -> BaSO4 + NaNO3[/CE] In order for us to write a net ionic equation for that reaction we must know what the solubility of the products are, in this case we know that all sodium salts are soluble ( as a general rule) and most nitrates are soluble, therefore NaNO3 will remain aqueous. However, not all barium salts are soluble, and if BaSO4 is looked up on the solubility table, you will realize that it is not a soluble salt. Therefore the net ionic equation would be as follows: [CE]Ba_{(aq)}^2+ + SO4_{(aq)}^2- -> BaSO4_{(s)} [/CE] Hope this helps

Hi, I'm having trouble making magnetite from FeCl2/FeCl3 and Sodium Hydroxide. I have a bottle of PCB etchant (FeCl3), put some in a beaker, added steel wool to reduce it to FeCl2. Then filtered, added FeCl3 and began adding NaOH. The problem is this: Iron Hydroxide is forming? I don't know how to stop that, I'm getting little Fe3O4 and lots of Iron Hydroxide. I thought it was the Etchant (impure) so I dissolved iron filings in HCl to get FeCl2. I added FeCl3.. and did the same procedure.. with the same result =( I'm not sure what to do? Any ideas on better ways of synthesizing Fe3O4 or where in can buy it (other than online of course , because i need it rather quickly) Thanks

Ah, I apologize, misread what you wrote. Right, I'll give it a shot then.

If you are referring to NaOH and I2.. Wouldn't that also produce Sodium Iodide ? Not pure Iodate? That means the percent yeild would be pretty bad?

hmm.. that's an Idea. I just recently bought half a kilogram of KI (not cheap) and im pretty much out of iodate. So I would probably use half of it to make KIO3, since I can't get a hold of it due to all the restrictions nowadays on oxidizers. Think NaOH and I2 is a more viable route in the synthesis of Iodate?

How well would this work with iodates? Obviously using KI instead of KBrO3 ?

From Wikipedia, I guess it isn't that bad, except in its radioactive form.

Yeah, This is what I think is going on: The HBrO2 conc. begins increasing (autocatalytic reaction).. the ferroin gets oxidized to ferriin (this is were the color changes from red to blue) then , as ferriin increases, it reacts and changes back to ferroin (why? I don't know.. probably has something to do with malonic acid.. but I havent completely thought it out yet) Br- is produced now, which inhibits the autocatalytic reaction. Stopping production of HBrO2. And it goes on like this.. Thats the best I can come up with for now.. since the BZ reaction is quite complex and im still trying to figure out some stuff. Edit: Oh, the mixture did not bubble when I did it. Maybe it is because I did it in a petri dish and it was too minute to observe?

Ok, I've been discussing oscillation reactions with woelen, and there are some interesting ideas using different methods. This is the link to the original thread: http://www.scienceforums.net/forum/showthread.php?t=23676 Another cool oscillation to try would be the Briggs-Rauscher Reaction. Unlike using ferroin to be able to see the change in color, with this you get the dark starch-iodine complex, and the oscillation goes back and forth from clear to dark blue. The chemicals required for this are: Hydrogen Peroxide Potassium Iodate Malonic Acid Manganese Sulfate Concentrated H2SO4 Starch This list is similar to that of iodine clock reactions, so for those familiar with it, this is almost the same with oscillation. I will be making a video of this next wednesday and report the results. Another interesting thing, which I tried today was a BZ reaction, except this time, I ONLY used Sodium Bromate, Malonic Acid, Sulfuric Acid, Ferroin. I tried this in a petri dish with only 5ml of solution total. My findings were as follows: For some unknown reason, this experiment did not work all the time, of the 4 times I tried this, it only worked once. The only reason I can attribute to this is contamination in the de-ionized water or the petri dish. I do not know. Also, the oscillation was very weird, I had started recording video footage, and for a while there was nothing, then when I put everything away and was going to clean up, the reaction began to oscillate. At least 15 mins before the start. I will be trying this again, and getting it on video soon. Anyone have any ideas on other 'oscillation reactions' or thoughts regarding this one. encipher

Yeah, MSDS is a good idea =D I'm looking for any ideas on how I can synthesize the compound at my home lab, or possibly at a laboratory if needed (I can get access if needed). I couldn't find much on it anywhere, not google, not wikipedia. I mean it must be snythesized SOME way, wondering if anyone knows how, or can point me in the right direction. cheers

Hi, Does anyone have any ideas regarding the synthesis of tetramethylammonium hydroxide [ce]N(CH3)4OH[/ce] ? I can't seem to be able to find a supplier of it, since nowadays restrictions are horrible here in the US. Thanks

Hi, I have a question regarding earthquakes. Does the rotation of the Earth have any effect on earthquakes? In any way.. I was thinking, Since the earth's crust are floating on magma, and not solidly 'attatched' the the core, if the angular velocity of one portion of the earth's crust is slower / faster than another portion, could that possibly cause shear i.e. an earthquake? Thanks

Hi, With regards to the first question, surface area does indeed affect the rate of the reaction, the rate of reaction increases as the surface area does. This is due to the fact that more particles are exposed to each other and they have more 'sites' at which they can react. The purple flame is characteristic of potassium salts (in this case KMnO4). Each element has its own unique emission spectrum. The flame excites the electrons of the Potassium, causing them to go into higher orbitals from their ground state. In order for the electrons to return to their ground state, they must release the additional energy in the form of light. Different metal electrons emit different wavelengths of light to return to their respective ground states, so the flame colors are varied. I wouldn't know the exact reaction that goes on with the KCLO3, sugar and sulfuric acid. So I'd wait for someone else who knows to reply

How would you figure out if this converges or diverges: 1/((n)(lnn)^2)

Yeah, a plumb bob is basically a weight. So its weight hanging from a thread. So how would I go about doing the "extra calculations" you speak of? Thanks again.

I'm trying to solve the following problem with little success: "A plumb bob does not hang exactly along a line directed to the center of the Earth, becaose of the earth's rotation. How much does the plumb bob deviate from a radial line at 35 degrees north latitude. Assume that the Earth is spherical" Help would be greatly appreciated. I would tips on how to start the problem off.. or a run through of the problem rather than just solving the problem itself. I'd like to work it out(well.. most of it anyways) myself. Thanks alot!

I think Silica also becomes less dense as a solid.. not sure about that through. Usually, one would expect, when a liquid freezes it would become more 'compact' because molecules are in fixed positions within a solid but require more space to move around as a liquid. The case with water however, is the structure it forms when it begins to freeze. The molecules within Ice's structure have a low packing efficiency. They water molecules form 4 straight tetrahedral oriented bonds. (I'm not sure about this, that's what I can remember, so if I am mistaken please correct me.) The reason water does this is because of the Hydrogen bonding that occurs between the molecules.

You ever watch a video of old hydrogen filled blimps go 'boom' ? Pretty damn fast, I don't know if such values exist (combustion rate of hydrogen & oxygen) but i can safetly say that it will burn faster than you can generate the two gases at any rate. I tried something similar with Acetylene buy 'dunking' chunks of calcium carbide in water and lighting the end from which the gas escapes. It burned out quickly.. stayed lit for a few seconds only. As for your comparison between the size of the flame to a golf-ball. If you are trying to produce a circular shaped flame, that is only possible in microgravity. Unless you can recreate such conditions, you are stuck with the standard conic type flame you usually see.