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  1. It won't affect the content (may be through evaporation)
  2. Design lab topic: temperature affecting vitamin c content in orange juice temperatures are 25°C, 35°C, 45°C and 55°C. I am going to be using starch to determine how much drops of iodine needed to oxidize it. Question is: will increasing the temperature affect the results (will it damage the starch n iodine content?) Thank you
  3. aDVnatgae


    Tom is scuba diving in his approach to Dr. Evil on his yacht. Tom uses a spear gun to shoot Evil in his heart. With the aid of a ray diagram, clearly show how Tom is to aim to his his target? I dont know where to start. can you explain in detail THANKS A LOT!!!
  4. I said MEAN (avergae) same process?
  5. Hi I have values like 4 grams, 3g,4g,9g,10g I measured this using kitchen scale. It does not say any uncertainty on the scale 1) So should I include uncertainty in the lab report (+- 1g)??? 2) If you are say do the uncertainty, then I have to calculate the mean for these numbers. What do I do? Do I have to first change uncertainties into percent uncertainties, then add them, then turn them back into absolute uncertainties for the final value??? My kitchen scale rounds rumber to nearest whole number
  6. I was reading about enzymes in our body that help digest food. I came across Pancreatic enzyme. Found in pancrease and they neutralize the acidic materials to meet the pH of our body. So I took a zip-lock and added pepsi to it. Then added the powder of pancreatic enzyme. Bubbles were formed. What is happening? Does it mean that the pancreatic enzyme got denatured??? Confused thanks a lot
  7. Wow I just did this lab in my chem class and forgot about it. This actually works so much better... AND one last questions. Would this work with carboxlic acid (acetic acid, proponic acid). What I mean they are weak acid and if I titrate a strong acid (naoh) using the 1/2 equivalence point. can I fingure out pKa? Thanks for all your answers.
  8. Is it possible to figure out the ratio for all 3? I calculate efficiency. Are the steps right and I dont know how to calculate the force of friction? This is the value I got for Trial 1: F (load) = 50 N this weight goes at the bottom of the pulley Y (load) = 0.13 m F (applied) = 30 N this weight is the applied weight Y (applied force) = 0.33 m *** Y are the distance travelled by the load and appied force W (load) = 50*0.13 = 6.5 J W (appilied/effort) = 30*0.33 = 9.9 J Efficiency = (6.5/9.9)*100 Is this right so far? How to calculate force of friction?
  9. http://dl.dropbox.com/u/7509061/WP_000418.jpg
  10. Take a look at the file that I have attached. Is it possible to figure out the ratio for all 3? How can you find Force of friction? and Egained (energy gained)?
  11. a) car runs into a wall and stops... where does the momentum go (cant be destroyed or created)??? b) you are on skates. someone throws a heavy ball? how does your speed compare to the base??? why? c) I am on frictionless ice will my bagback. How I can move (slide) before i freeze??? thanks
  12. I get what you mean. So if I calculate the pH when the solution is made. I will be able to calculate the Ka? But to do the experiment, how much water should I use to make a good enough H2CO3solution? Should I put a lot or less? thx a lot
  13. I have to design a lab for my chemistry sl class. Dissociation: H2CO3 + H2O HCO3− + H3O+ I have to find out how to calculate pKa experimentally ( by doing a experiment 1) Can I do it with acid-base titration? The thing is that H2CO3 is a weak acid. So I was wondering will it work or not. The base will be NaOH? And can I really find the pKa by doing the acid-base titration??? 2) Take a beaker but 20 ml of 1M of H2CO3. Then add water to it. When H2CO solution is made, you can find the pH will a pH meter. Then you can find the concentration of [H+]. This concentration can then go in the formul
  14. Can I increase the pH by adding water (diluting it) For my IA, I am going to use pepsi. The pH of pepsi is 3. How can I increase the pH? Our blood pH is 7ish. I have to somehow take it to there. Thank you. Chemistry SL
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