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    https://goo.gl/nVvgw9
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    anyone else bricking it
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    (Original post by Hunnybeebee)
    TMS - calibrate the spectra with reference peak at 0 ppm

    D2O - solvent to remove hydrogen from N-H, O-H by allowing them undergo proton exchange to remove them from spectra

    CDCl3 - solvent for compound about to undergo analysis

    Wrong or right?

    Posted from TSR Mobile
    Yes but if you wan't the stock answers here they are.

    TMS is used as the standard for chemical shift measurements

    D2O undergoes proton exchange (with labile protons e.g. OH, NH)

    CDCl3, a deutarated solvent, is used as it does not provide a peak
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    do we need to know that halogenoalkanes + NH3 (or amines) would eventually turn into a quaternary ammonium salt if NH3 is not in excess (or the halogenoalkane is in excess ) ?????? p.s. i hate spelling the word quaternary !
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    (Original post by Rust Cohle)
    Yes but if you wan't the stock answers here they are.

    TMS is used as the standard for chemical shift measurements

    D2O undergoes proton exchange (with labile protons e.g. OH, NH)

    CDCl3, a deutarated solvent, is used as it does not provide a peak
    Thank you!

    Posted from TSR Mobile
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    (Original post by lai812matthew)
    and solid amino acid = zwitterion ??
    A zwitterion is a dipolar but neutral amino acid from by the donation of the hydrogen atom from the carboxylic acid to the amino group

    Posted from TSR Mobile
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    In TLC how do you know about the solubility of compound? Like the higher the Rf the more soluble???? idk....
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    (Original post by Hunnybeebee)
    A zwitterion is a dipolar but neutral amino acid from by the donation of the hydrogen atom from the carboxylic acid to the amino group

    Posted from TSR Mobile
    got that one thx
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    (Original post by lai812matthew)
    do we need to know that halogenoalkanes + NH3 (or amines) would eventually turn into a quaternary ammonium salt if NH3 is not in excess (or the halogenoalkane is in excess ) ?????? p.s. i hate spelling the word quaternary !
    You'll just be able to need to say that ethanolic ammonia is in excess to prevent further substitutions

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    (Original post by Haydenator)
    In TLC how do you know about the solubility of compound? Like the higher the Rf the more soluble???? idk....
    the greater the solubility, the slower the component moves, cause it will be more attached to the stationary phase. Rf= distance move by component/ distance move by solvent, so Rf is smaller. and retention time longer.
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    (Original post by lai812matthew)
    the greater the solubility, the slower the component moves, cause it will be more attached to the stationary phase. Rf= distance move by component/ distance move by solvent, so Rf is smaller. and retention time longer.
    TLC has nothing to do with retention time. It's separation by adsorption.
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    Best of luck everyone 🍀
    • Welcome Squad
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    Welcome Squad
    Does anyone know if dilute, excess acid or alkali is used in any of the hydrolysis reactions? It keeps popping into my head and I can't remember what it's used for!!
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    (Original post by suibster)
    TLC has nothing to do with retention time. It's separation by adsorption.
    lol yeah sorry. so it would be the stronger the adsorption, the component binds more strongly. travels in shorter distance. Rf= distance move by component/ distance move by solvent. therefore Rf value decreases.
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    Good luck guys!! Hoping the h nmr is kinder than last year 😂


    Posted from TSR Mobile
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    If in GC and the stationary phase is a solid, then it separates by adsorption right?
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    (Original post by L'Evil Wolf)
    If in GC and the stationary phase is a solid, then it separates by adsorption right?
    Yes, that's correct
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    (Original post by L'Evil Wolf)
    If in GC and the stationary phase is a solid, then it separates by adsorption right?
    Yeah
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    (Original post by Lularose83)
    Does anyone know if dilute, excess acid or alkali is used in any of the hydrolysis reactions? It keeps popping into my head and I can't remember what it's used for!!
    almost every reaction uses conc acid except diazotisation which uses dilute HCl i think?
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    (Original post by lai812matthew)
    almost every reaction uses conc acid except diazotisation which uses dilute HCl i think?
    All hydrolysis reactions use dilute acid and alkali
 
 
 
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