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  1. H

    Chemistry: Post your doubts here!

    When preparing a solution of a fixed concentration from a given parent solution of concentration , say, 2.0 mol/dm3 A. We are required to prepare a solution of concentration of 1.0 mol/dm3 with volume 250 cm3 ( the concn cannot be greater than 2 !!!!!!!!!!!!!!) a. Add 100 cm3 of the parent...
  2. H

    Chemistry: Post your doubts here!

    so it does not matter which double bonded carbon atom is positive ?
  3. H

    Chemistry: Post your doubts here!

    I think you misunderstood. I meant that in the mark scheme they put the + sign on the carbon atom with one hydrogen atom. So the Br bonded to the carbon atom with two hydrogen atoms first. My question is if i put the +sign on the carbon atom with two hydrogen atoms and bonded the Br to the...
  4. H

    Chemistry: Post your doubts here!

    If i put the positive charge on the other double bonded carbon atom, is it wrong ?
  5. H

    Chemistry: Post your doubts here!

    explanation please ?
  6. H

    Chemistry: Post your doubts here!

    Explanation please ?
  7. H

    Chemistry: Post your doubts here!

    Do we have to know what affects the enzymes like pH temperature etc ? What exactly do we have to know about enzymes because i can't seem to understand it from the syllabus ?
  8. H

    Chemistry: Post your doubts here!

    For solution C, I wrote [Cu(NH3)4(H2O)2]SO4^2- But in the mark scheme it is Can you please explain ?
  9. H

    Chemistry: Post your doubts here!

    Can someone please give me notes on the biochemistry part ?
  10. H

    Chemistry: Post your doubts here!

    Isn't that the equivalence point ?
  11. H

    Chemistry: Post your doubts here!

    Can someone please draw this fully labelled ?
  12. H

    Chemistry: Post your doubts here!

    Starting pH is 11.9 and final pH is 1.8. Vertical line is at 15cm^3. Strong acid with weak base titration. How do we label the endpoint ? At the start of the vertical line or at the end or at the middle ?
  13. H

    Chemistry: Post your doubts here!

    How do we know if it is tetrahedral or square planar ?
  14. H

    Chemistry: Post your doubts here!

    Are these complex ions ? and if so when we draw the structure how do we draw the dative bonding ?
  15. H

    Chemistry: Post your doubts here!

    in 2014 may/june paper 42 mark scheme the optical isomers are given like this. In the syllabus, it's given that potical isomers should be drawn like this. My question is in the mark scheme why is the OH as a dashed line and then in the second isomer as a wedge but in the syllabus it is not ?
  16. H

    Chemistry: Post your doubts here!

    Can you please show me a sketch ?
  17. H

    Chemistry: Post your doubts here!

    Can someone please explain the second part please ? Why can it only be CH3+ why cant it be H2 or CH2?
  18. H

    Chemistry: Post your doubts here!

    Is there a specific reason why it started to curve at 10 and ended at 20 ?
  19. H

    Chemistry: Post your doubts here!

    Can someone please sketch this graph ?
  20. H

    Chemistry: Post your doubts here!

    Explanation for question (c) please ?
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