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    (Original post by master y)
    u're right. where is this q from/?
    Questions from the textbook
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    (Original post by KD35)
    You talking about the ionic product of water?

    If you are, it's similar. ka= [OH-][H+]/[h2O]
    As H2O is constant, they move it to other side and KAx[H2O]=Kw=[OH-][H+]
    oh I see, so its Ka in other words
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    Thanks
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    (Original post by master y)
    no need to be rude!
    He was acting like a smart ass
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    (Original post by otrivine)
    oh I see, so its Ka in other words
    Nope , Ka is for acids
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    (Original post by chignesh10)
    Nope , Ka is for acids
    and for water its ionic product, Kw
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    (Original post by otrivine)
    and for water its ionic product, Kw
    yup
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    How would you define neutral? Is it where the concentration of H+ =OH- ?
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    (Original post by Theafricanlegend)
    He was acting like a smart ass
    Rude!!! Meany!! Eww
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    (Original post by otrivine)
    How would you define neutral? Is it where the concentration of H+ =OH- ?
    Yep


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    Does anyone know if we have to memorise the transition metal ion colours on page 205 (Heinemann)Name:  ImageUploadedByStudent Room1370775239.985207.jpg
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    For questions asking to show the typical reactions of transition elements and the reactions, for the redox equation is writting:

    'Mno4- + 8H+ + 5e- > Mn2+ + 4H2O
    Purple > Colourless'

    Suffcient or should you include write a whole equation of for example when it oxdises Fe2+ > Fe3+.

    And quick question or everyone can you suggest the rest of the typical reactions of transition elements ?
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    can some help with january 11 Q3 E
    its giving me a headache.

    http://www.ocr.org.uk/Images/65361-q...d-elements.pdf
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    (Original post by tsr1994)
    Does anyone know if we have to memorise the transition metal ion colours on page 205 (Heinemann)Name:  ImageUploadedByStudent Room1370775239.985207.jpg
Views: 122
Size:  139.7 KB


    Posted from TSR Mobile
    You wouldn't need to know it. Just the facts that:
    Sc and Zn form colourless compounds becuase they form ions with complete d-orbitals.
    That Mn2+ is pale pink but appear colourless in solution.(because water is in excess) Mn7+ is purple which causes the purple colour of MnO4-.
    And finally not a must but from A/S u may need to know Cr6+ (from Cr2O72-) is orange, and Cr3+ is green.
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    would anyone be able to explain conjugate acid-base pairings? i still can't seem to work out which of the two reacting acids is more likely to act as a base
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    (Original post by scorpio22)
    can some help with january 11 Q3 E
    its giving me a headache.

    http://www.ocr.org.uk/Images/65361-q...d-elements.pdf
    This question is pretty simple, it is just about applying your knowledge which is difficult.
    It tells you each disulfide is broken down by 2 thioglycate ions to form 2 R-S-H and something else.
    SO:
    R-S-S-R + 2HSCH2COO- --> 2 R-SH and ?

    Now try to balance them out:
    They H must be taken from HSCH2COO-
    So you would get 2SCH2COO-
    Now you know that S can form disulfide bridges so:
    -OOCCH2S-SCH2COO-

    Part duex:
    H2O2 must reach with the R-SH to rebuild the bridges
    H2O2+2R-SH --> R-S-S-R + ?
    Look at what has changed
    H2O2+2H--> 2H2O
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    (Original post by s24a)
    would anyone be able to explain conjugate acid-base pairings? i still can't seem to work out which of the two reacting acids is more likely to act as a base
    Lower ka more likely to act like a b
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    (Original post by s24a)
    would anyone be able to explain conjugate acid-base pairings? i still can't seem to work out which of the two reacting acids is more likely to act as a base
    Usually gives the Ka values, the higher Ka is the acid. If not, as a general rule
    Nitric acids and Halogeno acids (HNO3, HCl, HF ect ) are more acid than Carboxylic.
    The shorter the carboxylic acid the more acidic so COOH > CH3(CH2)7COOH
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    (Original post by Better)
    Rude!!! Meany!! Eww
    Stop being a little ***** about it
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    (Original post by Theafricanlegend)
    Stop being a little ***** about it
    are you going to imperial?
 
 
 
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