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Search results

  1. M

    Biology P5

    Alright, respirometer people! I'm gonna be back with some good notes, expect a lot of good stuff!
  2. M

    Biology P5

    Look back in the thread. But if you are feeling too lazy, I can explain anyways. T-test is for continuous data using a normal distribution so it is a comparison using the means and standard deviation of data. Chi-squared tests use the actual data itself that has not been processed into a mean...
  3. M

    Biology P5

    Dude, calm down. Turn off the caps lock and please be friendly. Some of us require explanations and we are not ready to feed off the marks scheme so easily. Sorry if this is rude, but please, calm down. Thank you.
  4. M

    Biology P5

    So, we expect no change at all (as stated by the null hypothesis), so the results should be the same, regardless of how many years the grassland is left grazed or ungrazed (which is not even a word in the dictionary, CIE really needs to check what they write). So, whatever results we get, we...
  5. M

    Biology P5

    This is awesome stuff. Just use your knowledge in Biology to predict how to control the variables and how to measure them. Likewise, the constants must be appropriate to the context. The apparatus will always be something that you have seen or used before so please make sure you know how to use...
  6. M

    Biology P5

    Alright, let me give an entirely exam-oriented perspective at these statistical tests: 1) It is just math 2) They give you the formula, there is no memorisation required 3) It assumes you have knowledge on elementary statistics (i.e. mean, standard deviation) 4) It also assumes that you have...
  7. M

    Biology P5

    Speaking of balls, tips on alginate beads: - The solution you're mixing the enzyme to be immobilized with is Calcium Chloride - If you want even sized easy to use beads, mix the solution DROPWISE with the solution containing Sodium Alginate - The sodium displaces the calcium in CaCl, giving...
  8. M

    Biology P5

    Here's a list of how to keep a couple of variables constant: Temperature: - THERMOSTATICALLY CONTROLLED water bath - Air conditioned room - Incubator Wind speed: - Use of fan - Fan placed at same distance - Same Air speed of fan used I mentioned Light intensity and Carbon Dioxide concentration...
  9. M

    Biology P5

    - Whenever you are dealing with something relating to the light-dependent stage of photosynthesis, make sure you use a lamp at a fixed distance from the apparatus. Use a bulb of same wattage or use the same light-filter for the whole procedure (This, of course, is if you are NOT investigating...
  10. M

    Biology P5

    I got some Protips to help out. - Whenever there is an experiment that involves measuring quantities and comparing them, mention the use of a statistical test - Whenever you are to clarify the authenticity of a hypothesis using provided data, the lack of use of a statistical test is usually...
  11. M

    Chemo P5 tips

    Speaking of bungling, I am another victim of the straight line syndrome right here. It was just today that I learned to let go of that stereotype.
  12. M

    Chemo P5 tips

    Come on people! What rings more of a bell in mind: solubility line or solubility curve? Google both, let's see what you get :D
  13. M

    Chemo P5 tips

    Value for the loss in mass when reducing the temperature from 85 to 35?? I got a total loss of 14g. What did you guys get? And yes, it has to be a curve, as solubility can NEVER be negative, it cannot be a straight line because the solubility will only fall to zero at 0 K (absolute zero). So...
  14. M

    Chemo P5 tips

    Damn, it's time. I haven't looked at all of the past papers at all. I hope I will be able to use my brain to pull off at least a 25 for that A* my grades are hanging on, need it desperately! Although I'm sure P4 will put A LOT less pressure. We need to do this for P4 as well! Then I won't have...
  15. M

    Chemo P5 tips

    I took the mass of the basic carbonate used for the x axis as that was the independent variable and I took the mass of residue after heating for the y axis. If the basic carbonate is heated, the products are CuO, CO2 and H2O. H2O vaporises due to the heat, CO2 is a natural gas so the residue...
  16. M

    Chemo P5 tips

    After heating, all of the CO2 and water vaporise and they go, so only the mass of CuO remains. Use the data to find the mol of CuO for a value that is on the line of best fit. Then, since 1 mol of CO2 is produced with 2 mol of CuO, you can find the amount of CO2 that has been produced. Subtract...
  17. M

    Chemo P5 tips

    it depends on what you want to calculate. If it is the neutralization of the acid, use the acid, if base use base
  18. M

    Chemo P5 tips

    It is the energy gained per unit mol, so if you use more mols, you will get more energy right? So, to find how much energy one mol gives you have to divide the total by the number of mols.
  19. M

    Chemo P5 tips

    Dude, firstly, DO NOT PANIC! This is just an exam and usually you just need like 17 marks out of 30 to get an A so you will always be in the safe zone AS LONG AS YOU DO NOT PROCRASTINATE (which is hardly of the matter here because the exam's tomorrow). Anyways, getting to the point, when you mix...
  20. M

    Chemo P5 tips

    Enthalpy change of neutralisation, basically, is the energy lost (usually gained) when 1 mol of acid neutralizes 1 mol of base. It is different for every acid and every base. If you are to find the enthalpy change of neutralisation of something, use the standard plastic cup in beaker apparatus...
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