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AS Exams

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Slam to all
can anyone send some important informations, tips about practicals...chem 33, bio 34, phys 34
at [email protected] or [email protected]
and any guess(important topics or examiner trend ) about MCQs and theory of Phy, Chem , and bio ...

Thanks in Advance
 
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me 2 .. [email protected]

my practical papers are bio 33 .. chem 33 ... phy 33

is next week .. oh gosh ..

anyone knows any guides about chem 22 ? i kinda scare paper 2 .. especially organic compounds .. really stuck .. anyone can help ? have any good revision tips or method?

any comments is much appreciate . . :D
 
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as i hv mentioned earlier check out practical skills booklets for as ... available under subject codes here!
n do moles and thermodynamics 4 chem...
n here s any response u go search dis forum as it has all been uploaded several times by many ppl 4 many ppl! cheers
hope i helped!
 
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Ok Duh we're getting urease & urea tomorrow in Bio 33, Now what wud be the Improvements, Sources of error & Limitations for the experiment below?
Enzyme Concentration

In this investigation, we will examine what happens to the rate of a reaction when the amount of enzyme is reduced. We will use urease, an enzyme that converts urea to ammonia. The ammonia causes the pH of the water to increase (it becomes more basic). You will be able to tell when a reaction occurs because the urea solution also contains a pH indicator that is becomes yellow in acid but turns red when the solution becomes basic.

The object of this experiment is to measure the amount of time it takes for the solution to turn red if less enzyme is used.

C1. Create a hypothesis regarding the the amount of urease and the rate of reaction of Urea.

C2. Obtain four test tubes and add 2 cm of urea to each.

C3. Label three of these tubes 1 through 3; the remaining tube will not be used; it will serve as a control.

C4. Have your lab partner start timing as you add 15 drops of urease to tube #1 and then swirl the tube until it changes to a red color. Record the amount of time that it took for the urease to change to a red color.

C5. Add 5 drops of urease to tube #2 and then swirl the tube until it changes to a red color. Record the amount of time that it took for the urease to change to a red color.

C6. Add 1 drop of urease to tube #3 and then swirl the tube until it changes to a red color. Record the amount of time that it took for the urease to change to a red color.

C7. Record your results in the answer sheet.

C8. Did using less enzyme produce a reaction?

C9. What was the effect of using less enzyme in your experiment? If your experiment did not work as expected, what should have happened?

C10. In general, what happens to the rate of reaction as the amount of enzyme is decreased?

C11. Do your results support your hypothesis? Explain.
 
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Thanks for Bio help....
but mine bio is 34...lol
and i am tense about chem 33 on 12th may....just a single day left....can upgrade any help...guidance/tips...
thanks in advance
 
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chemistry33
hydrated ammonim salt titrated with KMnO4
usual salt analysis
one thermal question
 
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