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  1. Saad (سعد)

    AS Chemistry P2 Prep.

    They will accept both, but they will be more inclined to award an A* to the one they preferred and was correct, than the one that they accepted because it was just correct.
  2. Saad (سعد)

    AS Chemistry P2 Prep.

    The mole ratio of HCl and NaOH is the same, in the reaction: NaOH + HCl --> NaCl + H2O. So the number of moles of NaOH reacting with the HCl is the same as the no. of moles of HCl we used; 0.005. (In the question, we are told that we used 0.005 mol of Hydrogen Chloride. As the NaOH is in...
  3. Saad (سعد)

    A level Biology: Post your doubts here!

    As-Salaamu 'Alaykum. Any tips on what we should be careful of when performing the Bio Practical exam, and on what we should do for preparation, since there's only 1 day left now for Bio 34? Not asking for a guess paper or anything, just some general tips on what we should revise on the last...
  4. Saad (سعد)

    AS Chemistry P2 Prep.

    I know that... but we have to be considerate of what the Examiner likes more... if we want an A* instead of an A. o_o;
  5. Saad (سعد)

    AS Chemistry P2 Prep.

    Question; does it make a difference whether we write a carboxylic acid (say ethanoic acid) as CH3COOH, or CH3CO2H? Because I'm used to writing '-COOH', but the Examiner/Paper Setter always writes '-CO2H'... o_o...
  6. Saad (سعد)

    AS Chemistry P2 Prep.

    It does not remain an aldehyde... if you used reflux condition, its oxidized to carboxylic acid. If you distilled off the aldehyde as soon as it is formed without letting it oxidize, then it will remain aldehyde... otherwise the product of the oxidation of a primary alcohol is a carboxylic acid.
  7. Saad (سعد)

    AS Chemistry P2 Prep.

    Mine was good to the extent of getting almost full marks in every question... except the first. I think I'll lose at least 3-6 marks there... >_<
  8. Saad (سعد)

    AS Chemistry P2 Prep.

    22.
  9. Saad (سعد)

    AS Chemistry P2 Prep.

    The first question freaking... lost me lots of marks. >_< Everything else was easy, but tricky.
  10. Saad (سعد)

    AS Chemistry P2 Prep.

    Well, I found it very difficult... and I'm among the Top 5 smartest students in the school. >_<
  11. Saad (سعد)

    AS Chemistry P2 Prep.

    I don't think paper discussion is allowed before 24 hrs... is it?
  12. Saad (سعد)

    Chemistry: Post your doubts here!

    An acid that has a mineral bonded to a hydrogen. Like H2SO4 (sulfate is a mineral, hence sulfuric acid is a mineral acid); or HCl (chloride is a mineral, hence HCl is a mineral acid) and HNO3 (nitrate is a mineral, hence nitric acid is a mineral acid). But that's not the actual definition...
  13. Saad (سعد)

    AS Chemistry P2 Prep.

    Not if its heat under reflux. HOOCCOOH is what will be formed.
  14. Saad (سعد)

    AS Chemistry P2 Prep.

    Orange or yellow... preferably orange. beware of red; I haven't seen it being used by the Examiners. In book Cambridge-endorsed books and Mark Schemes, they've used orange, or in rarer cases yellow. We have to be careful to use the terms they like; orange is the safest.
  15. Saad (سعد)

    AS Chemistry P2 Prep.

    Sulfur dioxide has two bond pairs, one lone pair and one dative covalent bond. 2 bond pairs and 1 lone pair; that makes it bent at 117 degrees... I think.
  16. Saad (سعد)

    AS Chemistry P2 Prep.

    Thanks a lot littlecloud! Just one question. Are we supposed to take the specific heat capacity of water as 4.18 or 4.2? o-o; I always thought its supposed to be taken to 1 decimal place...
  17. Saad (سعد)

    AS Chemistry P2 Prep.

    How do you determine how many isomers there are for any given mol. formula? Is there any trick method or something, or a list of rules to follow to get them all down? I always seem to miss out one or two isomers in the questions when they tell you to draw all possible isomers for a given...
  18. Saad (سعد)

    AS Chemistry P2 Prep.

    I would like someone to help me understand that entire question; 3 (b) onwards. o-o;
  19. Saad (سعد)

    AS Chemistry P2 Prep.

    Don't fret yourself, its pretty easy, once you've figured it out. You've been doing this since O' Levels; just think, how does an ester form? And use your head.
  20. Saad (سعد)

    AS Chemistry P2 Prep.

    That's a very tricky question, and difficult to explain on here, but I'll try insha'Allah. X, as you know in part (c)(i), is OHCH2CH2COOH - it has an Alcohol group at one end, and a Carboxylic acid at the other. Basically, when you warm X with a little conc. H2SO4(aq) you get an Esterification...
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