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  1. sidbloom1995

    Chemistry: Post your doubts here!

    i dont know of a reaction between >C=C< with NaOH but with COO2H the H goes to the -OH of NaOH and form H2O and the becomes CO2-Na+ it will be a dehydration reaction! and no NaOH is not a functional group!! ( i still don get why you said that but so far that will be the ans. to it)
  2. sidbloom1995

    Chemistry: Post your doubts here!

    yes i agree!!
  3. sidbloom1995

    Chemistry: Post your doubts here!

    the answer is A check the description in the pics
  4. sidbloom1995

    Chemistry: Post your doubts here!

    when we react an aldehyde with Kr2Cr2O7, it gets oxidised and form -COOH (carboxylic acid) since in this part we have 2 CHOs, HOC-CHO, they both will turn into carboxylic acid, HOOC-COOH
  5. sidbloom1995

    Chemistry: Post your doubts here!

    about the acid or base part we have to see if the molecule is giving protons or accepting protons, H+, so it have to do with bronsted lowery base and acid definitions!! HPO4-2 have only 1 H and can accept one more (since we have H2PO4-) so it will act as a base and accept one more H+ to become...
  6. sidbloom1995

    Chemistry: Post your doubts here!

    what was your paper no.?
  7. sidbloom1995

    Chemistry: Post your doubts here!

    your answers are kind of long to answer and i cant draw it's shapes over here, but i'll tell you the method (e) with Na, the OH group in the molecule will give it's H away ad form [O-Na+] and the rest of the structure remains same with ethanoic acid it forms ester linkage, the OH group again...
  8. sidbloom1995

    Chemistry: Post your doubts here!

    it is not tetrahedral, it is non- linear and it is due to the lone pairs of electrons on the Oxygen atom there are two lone pairs and they both act on bonded pairs to make them bend to the angle of 104.5* remember when shaping a molecule, the number of bond pair and lone pair all count!!! (this...
  9. sidbloom1995

    Chemistry: Post your doubts here!

    structure of ice is very simple it only have 2 bondings in it, covalent and hydrogen bonding when water is freezing, these Hydrogen bondings arrange themselves in a hexagonal structure and form rings,giving ice an expanded volume and a fixed shape
  10. sidbloom1995

    Chemistry: Post your doubts here!

    in this one, H2PO4- ats like a base and donated electron and HPO4-2 acts as an acid the trick is that when a buffer reacts with an acid or a base, the product include the reactent of the other (this is some thing that i have noticed and is not a given rule, watch in the example) H+ + HPO4-2...
  11. sidbloom1995

    Chemistry: Post your doubts here!

    standard enthalpy cahnge of atomisation is when one mole of gaseous atom are formed from element in there standard states! suppose you have copper, Cu naturally in the environment it exit as Cu(s) but we convert it to gas by providing energy to it, thus it form Cu(g), the energy we provided is...
  12. sidbloom1995

    Chemistry: Post your doubts here!

    i see thank you!
  13. sidbloom1995

    Chemistry: Post your doubts here!

    this one is from the same one as before, o/n 2010 p42 to me the reaction seem same going by the molecular formula and i cant say how the structure will be so can someone just give me a drawing of it's structure??
  14. sidbloom1995

    Chemistry: Post your doubts here!

    the same paper as ok i get it but i used conc. H2SO4 with heat under reflux for ester reactions and since i saw this as esterification i did the same here ut was wrong!! can u please tell y we cant use H2SO4? Ohh and thank you for replying!
  15. sidbloom1995

    Chemistry: Post your doubts here!

    can someone tell me the reagenes and conditions for this part! from O/N 2010 42
  16. sidbloom1995

    Chemistry: Post your doubts here!

    how do we react H2O2 with KI and Cl2 with SO2 and form a redox equation using data from the data booklet?
  17. sidbloom1995

    Chemistry: Post your doubts here!

    yes i came across that myself just make sure that ur method is correct the mark scheme is wrongly printed i checked the previous data booklets and they also have 242 as long as ur procedure was correct u dont have to worry about the mark scheme using 244 instead of 242
  18. sidbloom1995

    Chemistry: Post your doubts here!

    HCl is a strong acid because it can be fully ionized HBr and HI can also be fully ionized but compare to HCl they are weaker!!
  19. sidbloom1995

    Chemistry: Post your doubts here!

    i have a doubt in october november 2010 p41 question 4 part c iii n iv can anyone answer it?
  20. sidbloom1995

    Admission for private candidates A level Jeddah HELP!!

    jeddah...the time limit is over now though T_T thx for asking tleast though :)
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