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  1. D

    paper 12 chemistry ...

    Sodium Ethanoate ( CH3COONa) is an organic compound !
  2. D

    paper 12 chemistry ...

    For all those people saying that ester hydrolysis question was 50, 50% thats wrong. Propyl Ethanoate on Alkaline Hydrolysis produces : C3H7OH and CH3COONa So Mass of C3H7OH = 60 g Mass of CH3COONa = 82 g Total Mass : 142 gram Now expressing as percentages. 60/142= 42.3 % 82/142 = 57.7 % Hope...
  3. D

    paper 12 chemistry ...

    When you substitute a cyanide ion, no of carbons increase, if you had put KCN you had end up with butanoic acid, but since the no off carbon atoms is same so it was NaOH(aq) followed by oxidation.
  4. D

    paper 12 chemistry ...

    that was a tertiary alcohol, they refluxed it with K2Cr2O7 , then it gave sodium with hydrogen, but didnt esterified with ethanol because it was an alcohol, it didnt reacted with 24 dinitro because tertiary alcohols are not oxidised. So in the end alcohol is the answer
  5. D

    paper 12 chemistry ...

    For the equilibrium one it was D
  6. D

    Discussion chem P12

    42.3 and 57.7 for sure, IT WAS C
  7. D

    Function of AS P1

    Another tip, that helps a lot and candidates often forget. When a line has equation in the form y=kx (where k can be any constant), the line passes through the origin and has no y intercept.
  8. D

    Function of AS P1

    Finding a range of a function when we get the function in the form a(x-b)^2 +c is pretty easy. Just notice the coefficient of the term 'a' given in the above equation. If its negative , the function has a maximum turning point If its positive , the function has a minimum turning point...
  9. D

    AS Chemistry Doubts

    Stereo Centre refers both to an optical isomer and cis-trans isomer
  10. D

    Chemistry: Post your doubts here!

    Answer is D. First check the oxidation of Nitrogen atom in NH4(+1) x+4=1 so x= -3 Oxidation of Nitrogen in Ammonium Ion = -3 Now Oxidation of Nitrogen in NO3(-1) x-6=-1 so x= 5 Oxidation of Nitrogen in Nitrate Ion is 5 Now Check the Oxidation State of Nitrogen in N20. 2x-2=0 so x=1 So...
  11. D

    Chemistry: Post your doubts here!

    For Question 11 you can see that the equilibrium concentration of Z decreases as the temperature is increased. This means that increasing the temperature lowers the forward reaction (or more simply the Kc for the reaction), and you must remember that Kc for exothermic reaction decreases with...
  12. D

    General paper A'S

    dont study :P hahaha
  13. D

    Need help on functions

    i can help u
  14. D

    Examiner Report unavailable?

    :D
  15. D

    AS Chemistry Doubts

    Please explain how is Question 39 done ? http://www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Chemistry%20(9701)/9701_w08_qp_1.pdf
  16. D

    AS Chemistry Doubts

    In that question, you can see that there are three side chains (arranged in rows), all having same structure, With 3 double bonds in each side chain. Now question says one side chain is converted to a compound with 2 double bonds. This means that one double bond has been broken so a mole of...
  17. D

    Lets Solve A's chem MCQ paper together.

    Here is the theory behind Question 16 : Basically in the electrolysis of brine, we use a diaphgram, so that NaOH and Cl2 do not react together. However, in this question it says that the products are reacted together, with THE CELL KEPT COLD. If you remember we have studied...
  18. D

    Add Maths Paper 22 Discussion

    well to be honest it was an easy paper..and went totally amazing mashAllah :D
  19. D

    physics paper..

    way tooo easy...... :D
  20. D

    Physics ATP

    donorsolutions: That was the answer to part (a) (i). I was talking about part (a) (ii). Thanks for the explanation though. Well!...focal length will be too large because as long as i think the distance is less (about 4 m) comparativley and therefore the rays wont be parallel ???
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