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Chemistry: Post your doubts here!

Discussion in 'International A And AS Level' started by XPFMember, Sep 29, 2011.

  1. Hajera

    Hajera

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    Need help with a Q5 (c) from Oct/Nov 2017 paper 41
    IMG-20180516-WA0033.jpeg Screenshot_2018-05-16-18-11-45.png
    Why is there no addition of HCl with the double bond?
     
    Last edited: May 16, 2018
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  3. Zaki ali asghar

    Zaki ali asghar

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    for that you need concentrated hcl and at rtp
     
  4. Hajera

    Hajera

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    but look at the 1st row. when excess Br2 (aq) is reacted with the molecule, addition does occur. even though they didnt mention whether it is conc or at rtp.
     
  5. Hajera

    Hajera

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    also in this question, why doesnt Br2 react with the double bond?
    bf51e59f-eeef-4ab5-87af-c7025cb9356e.jpg 7ffb172d-64e8-4333-a03c-e598749ecc3b.jpg
     
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  6. Krypton36

    Krypton36

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    Anybody got 9701_m18_qp_42 yet?????
     
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  7. ujjwal jha

    ujjwal jha

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    there is no reaction possibly of acid with alkene. please check!
     
  8. aermoid

    aermoid

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    if u have 9701_m18_qp_42 plz share
     
  9. Zaki ali asghar

    Zaki ali asghar

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  10. ujjwal jha

    ujjwal jha

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    here, from the spectra we can see there are 4 different carbon environment. so in isomer " R" there are 5 different carbon environment. while in isomer "S" there is only 3 carbon environment. as in isomer " T " there are four environment. hence it is spectra of isomer T
     
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  11. PixelsLevls

    PixelsLevls

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    There is definitely a reaction with Hydrogen Halides, and they are also acids. HCl reacts with Alkenes in gaseous state or mixed in water as a concentrated solution, which is basically hydrochloric acid. This is because the hydrogen will act as a electrophile, as it already has a slightly positive charge due to the electronegative chloride ion.
     
  12. ujjwal jha

    ujjwal jha

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    sorry , i had misunderstood your question
     
  13. haithsoul

    haithsoul

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    how was chemistry paper 4, 42 guys?
     
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  14. Zaki ali asghar

    Zaki ali asghar

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    Quite good, was easier than the last year.
     
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  15. Metanoia

    Metanoia

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    There are only 2 unique ways to place the 2 Cl atoms, either 180 degrees from each other or 90 degrees
     
  16. haithsoul

    haithsoul

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    yeah its was, lets discuss what was the ph? for first question?
     
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  17. Zaki ali asghar

    Zaki ali asghar

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  18. Zaki ali asghar

    Zaki ali asghar

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    Temperature was 2836 and volume 448cm^3
     
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  19. haithsoul

    haithsoul

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    yes i have same temperature and volume but different ph. how did you get 1.6 mine was alot higher
     
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  20. Zaki ali asghar

    Zaki ali asghar

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    after finding the moles you had to calculate the conc using n*1000/800 and then the ph formula
     
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  21. haithsoul

    haithsoul

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    how did you find the concentration for the OH?
     
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