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  1. Dreamerish*~

    What is the structure of Polyhydroxybutyrate (phb)?

    This is a section of the biopolymer PHB:
  2. Dreamerish*~

    Decarbonation of soft drink

    You should never freeze a bottle of soft drink because the solubility of CO2 in ice is very low. So almost all the CO2 is going to come out of solution as the water freezes out, and pack into the small space under the cap. This would cause a significant build-up of pressure, and possibly an...
  3. Dreamerish*~

    decarbonating sogt drink (using salt or heating?)

    The mass of CO2 lost is usually around 1 g (in Jamesy's report it was 1.5 g), which is much less than a teaspoon of salt. The salt would cause not a negligible, but quite a significant change in mass.
  4. Dreamerish*~

     classify common substances as acidic, basic or neutral

    Then the equilibrium won't be affected by the change in pressure.
  5. Dreamerish*~

     classify common substances as acidic, basic or neutral

    When the total pressure is increased, the equilibrium will shift to the side that has less moles of gas. If you look at the equation, on the left there are 4 moles of ammonia and 5 moles of oxygen gases, making 9 in total. On the right, there are 4 moles of nitrogen oxide and 6 moles of water...
  6. Dreamerish*~

     classify common substances as acidic, basic or neutral

    Not much. You should know that common substances such as vinegar, lemon juice, stomach acid, and to a lesser extent milk and saliva are acidic; and that detergents, shampoo, soap, household cleaners, and even blood are basic. That's it, really.
  7. Dreamerish*~

    Hallo?

    I don't want to forget German, but I don't know how I can stop myself from forgetting. I just don't have the time to practise. :(
  8. Dreamerish*~

    decarbonating sogt drink (using salt or heating?)

    Adding NaCl will reduce the solubility of CO2. I don't know exactly why. However, it's not recommended for this prac because your aim is to find the difference in mass caused by the loss of CO2. Adding salt will interfere with your mass measurements and produce a result that isn't valid. Heat...
  9. Dreamerish*~

    Chemistry Tritation, Chemistry Olympiad, RACI

    Do you mean titration? You don't need any books for titration. It's in the HSC course, just look in your textbooks.
  10. Dreamerish*~

    Biopolymers

    PHB stands for poly-β-hydroxybutanoate, which is a member of the group PHA, which stands for poly-β-hydroxyalkanoate. It's like butane belongs to the homologous group alkanes.
  11. Dreamerish*~

    Inter and Intra molecular bonds

    Covalent bonds are intramolecular bonds, while dipole-dipole, dispersion and hydrogen bonds are intermolecular bonds. You separate the hydrogen atoms and oxygen atoms in water by electrolysis. Dispersion forces is just one type of intermolecular bonds. Others are dipole-dipole and hydrogen...
  12. Dreamerish*~

    Biopolymers

    http://community.boredofstudies.org/17/chemistry/46990/i-wondering-if-anyone-had-any-notes-biopol-pha.html?highlight=biopolymer http://community.boredofstudies.org/239/production-materials/55629/how-answer-monster-dot-point.html?highlight=biopolymer...
  13. Dreamerish*~

    Wait wait wait, we can't be friends?

    I agree that in most cases, close friends of the opposite sexes have had thoughts of taking it further cross their minds. It's not impossible for opposite sexes to be best friends, but it would probably be hard if they were both single and attractive. Personally I've never been able to stay in...
  14. Dreamerish*~

    What Size Are You?

    Tops: 6, xs or smaller Pants: 6, xs Shoes: 6-7 Contrary to what my sizes suggest, I'm not a stick. I'm just petite (160 cm). Personally I find most really skinny girls less attractive than curvy girls. But attractive curviness means boobs and ass, so you get a nice "S" shape.
  15. Dreamerish*~

    ASSESSABLE PRACS (The Acidic Environment)

    Yeah, but you don't know your sciences. :rolleyes:
  16. Dreamerish*~

    ASSESSABLE PRACS (The Acidic Environment)

    POM, CMM, POM, and CMM. :p
  17. Dreamerish*~

    Esters- Structual Formula and Other Problems

    The H+ comes from the -COOH (carboxylic) group of the alkanoic acid, and the OH- is simply the -OH (hydroxy) group of the alkanol. R1-COO-R2, where R1 and R2 are alkyl groups originating from the alkanoic acid and alkanol, respectively. There isn't one, because esters can be made from any...
  18. Dreamerish*~

    help with isotopes plz..

    Technetium-99m Benefits: Useful in diagnosis in medicine. It can assist in the diagnosis of blood clots, tumors (including brain tumors), thyroid abnormalities and bone diseases. It can also be used to assess the damage of the heart after heart-attacks. It has a half-life of 6 hours, which is...
  19. Dreamerish*~

    Past- Half yearlies

    The contents of half-yearly exams vary from school to school, but I'm sure that most schools would give questions as similar to HSC questions as possible. So basically half-yearly past papers are just questions from whichever modules you've completed so far, taken out of the HSC past papers. :o
  20. Dreamerish*~

    staying awake

    Sleep early (10:00 pm) and drink lots of water. Make sure you get up early enough to eat slowly and sufficiently in the morning, because a lot of people feel more tired during the day if they skip breakfast. It's not healthy to rely on caffeine for energy anyway.
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