Jump to content


Senior Members
  • Posts

  • Joined

  • Last visited

Everything posted by encipher

  1. How is Phosphoric acid stronger than nitric acid? Phosphoric acid is clearly classified as a weak acid, and nitric as strong.
  2. I've been using Vista since the day it went RTM, and I absolutely love it. Now, before I can express my personal opinion towards the OS, I will make clear what exactly i do on it. I have several computers, one of which is an AMD X2 4800+, with 1 GB of DDR ram. It's my primary development computer. I run Visual Studio 2005, Microsoft Office suite, Multiple Adobe products (including premiere, after effects, photoshop, dreamweaver) for video post production purposes. I almost always have 10+ applications running simultaneously. I've also just started using Windows dreamscene. I'm also running full vista aeroglass As you can imagine, I do quite a bit of rendering on the system, a lot of compiling etc.. and It has yet to crash. It has been very solid from the very beginning, I have disabled UAC which is a pain in the butt, but without it everything runs smoothly. Performance is great (again 1 gb of ram). However, there are a few issues I do have with vista: 1. I have about 3 TB worth of raw footage and other stuff on the system, especially when capturing off DV media, vista lags a great deal. 2. Search indexer puts a lot of strain my drives. I do a lot of data transferring as is, and with indexing my pc can sometimes come to a screeching halt. I have since disabled indexing and haven't had any problems like that again. 3. Explorer window listing.. For some odd enough reason, it can never remember my preferences (show file type, size, date modified etc..) and its reallly annoying. Asides from those three points, I have had no issue with vista and I recommend it to almost everyone. My belief is that, as usual, people are afraid of change and look for any excuse not to move to the newer and better solution. I haven't had any compatibility issues with software/hardware although I have read about it a lot. I guess I might just be lucky, but who knows...
  3. Generally, Epsom salt is actually the heptahydrate (seven waters) of Magnesium Sulfate MgSO4·7H2O
  4. Riogho, Thanks for that explanation, however I am interested not in Oxyacids but in Binary acids.. I am aware of the reasoning behind the strength an oxyacid in relation to electronegativity. I want to know the effect (if at all significant) on the acidic strength of a given GROUP, specifically, 7A. i.e. HF, HCl, HBr, HI Thanks
  5. I'm aware of that, my question however is regarding its effect on the strength of an acid going down a group.
  6. Hi, Does electronegativity play any significant role in the strength of the acids in a given group? (particularly Group 7A binary acids) I know the general trend across periods... But I'm curious as to wether or not EN has a significant effect down a group. Because HF < HCl < ..... Thanks
  7. Hi, I am interested in getting a quantitative result (mathematical figure) on the maximum "holding capacity" of water. i.e. If I had 1 L of H2O, whats the maximum concentration of ions can exist before a precipitate starts to form. And I am not talking about individual Ksp's of salts. Lets say you dissolve the maximum amount of NaCl in the 1L of H2O, then the max amount of KF, then LiI.. etc.. What is the limit of water in terms of the concentration of ions it can hold ? Thanks.. P.S. This is NOT a homework problem.. I'm just curious.
  8. encipher


    Don't forget the napalm using frozen orange juice and gasoline (fightclub).
  9. From Wikipedia (http://en.wikipedia.org/wiki/Sublimation_%28chemistry%29): The same happens during deposition (condensation is from gas to liquid, not solid). This does not mean that there doesn't exist a liquid phase for those compounds. Depending on temperature and pressure, there are a wide variety of chemicals that exhibit sublimation if the pressure of the environment changes. To understand more about this check out wikipedia's "phase diagram" page.
  10. Yes, however they are only suggested. However, the goal is to find labs that are more realistic, as in they will help students get a feel of what goes on in the chemical industry. Labs such as taking copper wire, placing it in a flame and watching it glow don't exactly do the job.
  11. Hi, I'm doing some volunteer work at a high school over the summer and will be preparing labs for the AP chemistry students next year. I'm looking for ideas on fun, interesting and informative labs that a high school student can do in class. Time is not an issue if it is a very good lab. I'm particularly looking for labs involving fractional distillation and simple distillation, at least one of each. Thoughts are greatly appreciated. I'm not looking for a whole write-up or procedure, as that is part of the work I will be doing. Labs that are visually appealing and/or intellectually stimulating would be the best. Thank you.
  12. Looking through that thread, I think most of the people who posted on that thread there should stick with physics... =) Anyways, It doesn't answer my question of whether or not the reaction is shock sensitive, I mean I've seen millions of videos online of teens putting that stuff in coke bottles and blowing chunks of their hands off.. but would it simply go off merely by handling a container with the reactants?
  13. No, despite the title, this isn't a kewl post Last friday, at the local highschool where I live, a less than intelligent high school senior decided to make an infamous chlorine bomb, and leave it in the boy's bathroom. A teacher came in, saw an OPEN bottle and a horrible smell, picked it up (it was hot) and WOOSH, was engulfed in nasty fumes. He was taken to the hospital and treated. The suspect was apprehended by the police and it was found that he had mixed alcohol and chlorine pellets. My question is this: Why was there a big and sudden expulsion of gases when the container was picked up. Is it shock sensitive? and how does the reaction proceed? Does it produce alkyl chloride? or simply CO2 gas? if so, was it the fact that CO2 gas carried the hypochlorite with it that caused the irritation to the lungs etc.. Thanks
  14. Look into Patinas for metals. IIRC, the 'mix' for blue is as follows: Mix sulfurated potash and ammonium chloride in about a quart of distilled water. I believe the ratio is 3:40 by mass. I'm no expert on this, but googling Patina formulas could help? Check out this wiki article: http://en.wikipedia.org/wiki/Patina
  15. Dewar/Vacuum flasks are commonly used to store cryogens (such as liquid Nitrogen or Oxygen). The following was taken from the Wikipedia article on Dewar flasks:
  16. Hi, Does anyone know of a good composition that will generate copious amounts of smoke, and doesn't have much if a flame. It will be ignited in a sealed container with a hole from which the smoke should exit. (Will the confinement cause the mix to explode rather than deflagrate?)
  17. encipher

    Slow Yoyo

    Yes actually, I spoke to them after I came back from my vacation. The design they were talking about was an axle, and two cylinders on each end. Inside the cylinders on each end was water, and a series of segments. (imagine a waterwheel, but closed and there is water in one of the sections.) as the yoyo rotates, there are tiny holes in each flaps that allows water to flow slowly from one section to the other. That is how it took a very long time to reach its destination.
  18. How could silver be present, if when NaCl is added, no precipitate is formed? AgCl is insoluble, remember. therefore if a chloride salt is added to a solution containing the Ag+ ion, it will precipitate out AgCl. Therefore the only remaining answer is Fe3+, since only iron(III) hydoxide is the only insoluble Fe salt out of those three.
  19. I didn't quite understand your explanation. But what I will say, is that AgCl is insoluble, and BaSO4 is insoluble, and that hydroxides are insoluble except Group IA, NH4+, Ba2+, Sr2+, Ca2+ and Tl+ hydroxides. Now see, with this information, if your answer matches those criteria.
  20. The overall reaction is as follows: [ce]AgNO3_{(s)} + HCl_{(aq)} -> HNO3_{(aq)} + AgCl_{(s)}[/ce] Since HCl is a strong acid, and it dissociates readily in water, it needs to be broken into H+ and Cl-. Also, Since HNO3 is a strong acid and dissociates readily, the same should be done. You will then notice that H+ is both in the reactants and the products as an ion. Therefore it is a spectator ion and can be eliminated. The net ionic equation would then end up being: [ce]AgNO3_{(s)} + Cl^-_{(aq)} -> NO3^-_{(aq)} + AgCl_{(s)}[/ce] Hope this helps
  21. Woelen, That's odd. The first Chlorate/Perchlorate I got was Ammonium Perchlorate. I still haven't used it all up either. Its fairly easy to obtain here in the US if you know the right suppliers. I didn't even pay hazmat shipping for it.
  22. budullewraagh, I get your point, you and woelen are correct. The point to what I was saying, was basically if someone was asking a simple question of that sort, factors such as those you and woelen just mentioned are probably not what is being looked for. Although I see how, if that wasn't mentioned a person could have a wrong interpretation of this. Thanks
  23. Woelen, Pure ionic bonding does not exist. All bonds have some degree of covalent or metallic bonding. It is the same with a lot of covalent bonding. Due to differences in electronegativaty, so called 'covalent' bonds aren't COMPLETELY covalent. But for the purpose of his question, I think that is an reasonable response.
  24. No, they are incorrect. You must remember that each orbital much hold a certian amount of electrons before electrons begin filling an orbital of higher energy level. The S subshell can only take 2 electrons. The P subshell can only take 6, the D subshell can only take 10 electrons etc.. Therefore, if an atom has 8 electrons it would be as follows: 1S2 2S2 2P4.. as for the 2P4, there are two electrons in Px, 1 in Py and 1 in Pz Now, using that info, try to do an atom with 10 electrons.
  25. Its fairly common. Examples would be Phosphate anion (-3) The aluminum cation (+3) Iron can be +3 Lead can be +4 Tin can be +4 Cobalt can be +3 Nitride is -3.. These are a few examples. There are many more.
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.