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  1. Casablanca

    Why bother

    No one forced you to come here, so stop showing off how butthurt you are that we're going to end up with better grades than you. U mad, cuz we be stylin' u, brah?
  2. Casablanca

    Chemistry: Post your doubts here!

    Hmm, that sounds strange. Are you sure they all have a double bond though? Because it asks for ones with a double bond.
  3. Casablanca

    Chemistry: Post your doubts here!

    Oxidation no. of N is -3. Oxidation no. of H is +1. Oxidation no. of O is -2. Sum of oxidation no.s in a compound must equal zero. When you calculate it, C is the only option. Because, look: NH4ClO4 -> -3+4+x-8=0 -> 1+x-8=0 -> -7+x=0 ->x=7
  4. Casablanca

    Chemistry: Post your doubts here!

    How many isomers with the formula C5H10 have the structures that involve pi bonding? A- 3 B- 4 C- 5 D- 6 shouldn't the answer be 2? But there is no option 2, so it can't be. What is the answer and why? --- The products obtained by cracking an alkane, X, are methane, ethene, and propene...
  5. Casablanca

    Chemistry: Post your doubts here!

    I THINK the answer is 2. Because number of isomers = 2^n and n is the number of double bonds. In the case of C2H2Cl2 we only have one double bond, so 2^1 is 2. But I think you should wait for someone to confirm it, because I'm not that good at chemistry. :P
  6. Casablanca

    Dilutions-Biology As Level

    The revision guide is the best way to go about it, but basically what you do is: For example, they ask you to measure a cell... Instead of measuring one cell, you measure five cells. So line up the scale such that five cells fit in between two bold lines. Let's say your reading was 5mm and...
  7. Casablanca

    Essential Biology Practical Skills-Don't MISS OUT!!

    Mine's in less than 12 hours from now. *gulp* :unsure:
  8. Casablanca

    Essential Biology Practical Skills-Don't MISS OUT!!

    I'm doing 33.
  9. Casablanca

    Dilutions-Biology As Level

    Start reading from page 100 of the revision guide by Mary Jones. It's not that hard.
  10. Casablanca

    Essential Biology Practical Skills-Don't MISS OUT!!

    I can't provide a picture, but basically, in a plan diagram, you're supposed to show how a tissue works as a whole. So, no drawing individual cells, just tissues. No shading, only clear, unbroken lines, correct labelling, etc.
  11. Casablanca

    Guess for bio practical 33????????

    None are sure. It's just what I've heard from friends, and read on here/
  12. Casablanca

    Chemistry: Post your doubts here!

    Thanks.
  13. Casablanca

    A level Biology: Post your doubts here!

    Depends on the least count of the measuring device. It doesn't have to be a whole number, could be 2.12 or 4.3 or whatever. Edit: But try to round it, because that's what I heard.
  14. Casablanca

    Chemistry: Post your doubts here!

    In the past paper you're doing, do you know the answer for 14? The question about the graph of acidity of period 2 oxides. Is the answer A or B? (or something else?)
  15. Casablanca

    Chemistry: Post your doubts here!

    Are you sure it's B and not C? I thought the answer to this question was C, since Mg is in the same period, and according to the book, their electronegativity is similar. :/
  16. Casablanca

    A level Biology: Post your doubts here!

    Could someone please link me to pictures of some of the more common slides we're going to need to identify? Thanks in advance. :)
  17. Casablanca

    Chemistry: Post your doubts here!

    MgO is soluble. MgO(s) + H2O(l) -> Mg(OH)2(aq) (weakly alkaline solution) Al2O3 does not react or dissolve in water. However, it reacts when added to acids or alkaline solutions. But still insoluble in water.
  18. Casablanca

    Guess for bio practical 33????????

    My friend told me that we're going to have whisking tube and microscope, and group 34 is going to have sucrose, catalase, and microscope. I haven't studied for whisking tube at all... :/
  19. Casablanca

    Essential Biology Practical Skills-Don't MISS OUT!!

    In both, test for reducing and non-reducing sugars, it's positive if blue Benedict's solution turns brick red. How can this be? Should results be different? Or is it actually like that?
  20. Casablanca

    significant figures

    Because, like I said, you're allowed to add in one more sig. fig. for accuracy. Or maybe they want to keep it uniform. For example, if most readings are in 3, they might add a third s.f in ones which there are only 2. For the sake of simplicity stick to 2, like I do. I always get good grades...
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