question

  1. Z

    Periodic Table question

    Hi. Please see attached file, first table it's real periodic table. Second table is my own. There is any sence in what I done? Many thanks in advance.
  2. V

    I got a question. Im new here

    Hello chemistry forum! Im so excited to be here. So my question is about vacuum drying. Im not even sure it applies here. Anyway, can you vacuum vegetable oil or coconut oil? And will it alter if not destroy some of the properties in the oil? VincentD
  3. K

    Hello, got a question...

    Hi, I'm a science fiction writer (oh, no, not another one of those!). Yep! And I need help on a short story that I'm working on. I have human settlers trying to establish a colony on a distant planet. Their ship is on the surface and mostly intact. The surface of the world is adequate for...
  4. G

    Soap Saponification Question

    Hi, I'm trying to understand what chemically happens when soap is made with rancid oils (fatty acids). No one ever seems able to answer it, so I'm hoping someone here can help (I'm not studying chemistry, I make soap). In a typical batch of soap, you add lye solution (NaOH+H2O) to a fatty acid...
  5. L

    Neutralisation question on the equation

    I was just having a look at this reaction and couldn't work out the equation, can anyone help me out? HSO4 + NaOH <--> Na2SO4 + H2O
  6. T

    Question about potassium permaganate

    2 days ago, I poured a few grams of potassium permaganate crystals (from brumer) into some warm-hot water. A friend said it would my crushed toenail heal faster. I searched up some of the downsides of using potassium permaganate and I regret using it. How do i know there's no more left on my...
  7. L

    Help with Kp question

    Can anyone help me with this question? I have calculated the equilibrium moles and mole fractions and also written an equation for kp but don’t know what to do next. “in the following reaction 4.0 moles of PCl5 is heated. At equilibrium there are 2.7 moles of PCl5 remaining. Given that the value...
  8. Sammy

    Lab Question

    I have to do a chem prelab for this week and two of the questions ask for specific reasons behind the procedure and method. Part of the lab procedure is to find the mass and volume of three glass rods- one small one, and two large ones with different lengths. Another step is to find the mass and...
  9. D

    Stock Solution Question

    If I have a a 40% solution and a 95% solution, how much of each do I need to make a 70% solution with a final volume of 375 ml? My 30 credits in chemistry was too many years ago and I'm out of practice (and stuck.). I've been playing around with the stock formula and algebraically rearranging...
  10. J

    conversion question

    What is the conversion of in Hg to torr? If it helps, the problem this conversion comes from is as follows (summarized): barometric pressure is 30.45 in. Hg. (a) convert this pressure to torr. (b) convert this pressure to atm. The conversions the book gives in regards to pressure are as...
  11. A

    Question about ammonia and TAN for a small experiment

    Hello! I am trying to set up a small experiment for my class but I am stuck on a problem. We have three saltwater tanks, with the following measurements: The first tank will have a pH of 7.5, an NH3 level of 0.06 mg/L, and a TAN (total ammonia nitrogen) level of 20. Just NH3 is added. The...
  12. R

    Question About Naming Molecular Compounds

    Okay so I have started this debate with my Chemistry Teacher about how you determine if a compound is Ionic or Covalent. I was basing on how I name a compound based on the Electronegativity. Based on the χ<0.4⇒ covalent non-polar 0.4<χ<1.7⇒ covalent polar χ>1.7⇒ ionic So for example on PbI2...
  13. E

    Simple solution question

    Hi all, I have a very simple problem but for some reason I am having trouble with it. I need to dope 0.5g of solid powder with element X to a concentration of 500ppm. I have a solution containing 1000ppm element X. How many mL of this solution do I need to add to the 0.5g of powder in order to...
  14. O

    Practical question

    I have a question I hope some of you may be able to help find an answer to. In my hobby I use a whetstone to polish carbon steel blades. I have a SEM chart of what the whetstone is made out of. I use the whetstone with water on carbon steel blades...that's basicaly Carbon in a cristaline Fe...
  15. G

    How to calculate final temperature question.

    Hi, I am new to this forum. I am not pretty sure about the answer i got so i came to here in order to get help. Iceman, a member of the Marvel superhero team known as the X-men,enters a friendly duel with the Human Torch (Fantastic Four), and gets hit by a fireball worth 562kJ. Ice man is...
  16. N

    New user..sodium metasilicate question

    Hello to group.. I ordered and received a screen protector for my new iPad. It arrived cracked. Holding this item it is extremely light and cracked, it appears like, and feels like acrylic. I wrote to the manufacturer and told them they sent me plastic while the item is marketed as tempered...
  17. N

    A question about thermodynamics

    I'm not sure what the answer is, all of my friends and my chemistry teacher said it is A, I think it is obvious that the graph is talking about 2 catalysts so it could be D. But I have no idea what the E_a thing is, I've tried googling it to no avail. I got this question on an advanced...
  18. Y

    Difficult buffer question...

    Question - You will prepare 2 buffer solutions, one which is pH 5.2 and one which is pH 8.8. Solutions available: 1M NH3, 1M NH4Cl, 1M ethanoic acid, 1M sodium ethanoate solution. Calculate how much of the above solutions you need to make 100cm3 of each buffer. Use the equation pH = pKa - log...
  19. M

    Desperate help.reactor calculation exams question

    can some one help me here, This question is definately coming to my exams but do not understand it please. how you go the answer i would appreciate it please. please desperate help. An open straight-blade turbine of diameter 0.82 m is used to stir reaction mixtures in a 20 m3 batch with...
  20. G

    Redox Half Cell System Question Help

    The answer to this question is E C D, from top to bottom, but I don't know why. Can someone explain? http://prntscr.com/hx040h