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Sourav posted an Question
August 30, 2020 • 16:52 pm 30 points
  • IIT JAM
  • Chemistry (CY)

More stable the bond, the more is the bond energy na?

Arrange im order of -H bond energy H-CH2 HCH-CH-CCH H

2 Answer(s) Answer Now
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  • Narayanarao gundoju

    e>a>c>b>f>d

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    how

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    based on stability of carbocation

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    plz show how

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    stability order is benzylic > 3> 2> 1> sp2ch

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    more stable more bond energy na?

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    d is most stable coz of reso snd +I effect.

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    yes

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    so how your e is most stable.. it is least stable na coz of free radical on double bond

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    yes it is least stable among this

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    but you wrote e has most c-H bond energy

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    yes more stable less bond dissociation energy

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    why so.

  • comment-profile-img>
    Priyanshu kumar best-answer

    https://www.toppr.com/ask/question/9arrange-in-order-of-ch-bond-energyh-ch2hchchcch3h-the-following-the-total-number-of-compounds/ check this sourav

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    check by homolysis bond cleavage

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    by considering free radical stability

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    Got this sourav??

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    but sir by that only i solved it.. my answer is coming in opposite order. can you check plz

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    okk wait

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    a becomes least stable na primary free radical

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    b tertiary free radical

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    c secondary

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    E has free radical on double bond

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    f benzyl free radical

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    d how double bond??

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    typing error

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    e should be least stable na.. coz free radical in double bond.

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    wait

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    sourav here free radical is resonance stabilised in case of e ..so most stable

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    how can this be reso stablised

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    sorry....benzyl one is reso stabilized

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    d should be most stable na coz of reso and +I effect.

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    order given is what e most and d least??

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    yes sir

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    order gets reversed by considering free radical stability

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    why sir.

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    sourav think agar bond tutne ke baad agar jyada instability aa jaye to wo bond tutna nhi chahega so hmko jyada bond energy lgana hoga bond break krne ke liye

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    so if it is gone towards instabilty then more bond energy required

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    when we consider e we have least stable free radical...so it require more bond energy

  • comment-profile-img>
    Dinesh khalmaniya 1 Best Answer

    yes,. more stable the more, more is the C-H bond energy

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    to check bond energy, remove the and check the stability of - charge

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    why - charge sir?

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    because, here after removal of H, negative charge obtained

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    because here we are checking strength of C-H bond, so we will check, the stability of carbanion

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    i thought we will check the strength of free radical

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    yes, you can check the stability of free radical also. results will be same because same factors such as resonance, inductive effect, affecte the stability of FR and Carbanion

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    sir but if im checking stability of - ve charge, answer is not coming. kindly check

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    yes, wait

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    d is most stable and e is least stable

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    how sir.

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    answer is e most stable d least stable

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    wait..

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    check it

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    Sourav more the stability of Free radical, less is the bond strength of C-H bond. because if H FR can is removed easily if the carbon FR is most stable

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    got it?

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    so least stable bond will have more bond energy?

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    here we will check bond dissociation energy of bond so we need homolytic cleavage

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    but sir we have learnt that more stable is the bond, more is the bond dissociation energy.

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    yes, but we will check it by the stability of FR na?? less stable the free radical more stable the bond??

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