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    need help in part b

    for a number of molecular ions peak, I think there will be 4 (4 combinations)
    for m/z value is it 320 (I have no idea)

    can someone please explain me that
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    (Original post by Qer)
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    need help in part b

    for a number of molecular ions peak, I think there will be 4 (4 combinations)
    for m/z value is it 320 (I have no idea)

    can someone please explain me that
    It's just statistics.

    Four chlorines
    Two isotopes

    How many possible (unique) combinations

    37, 37, 37, 37
    37, 37, 37, 35
    37, 37, 35, 35
    37, 35, 35, 35
    35, 35, 35, 35
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    Imagine you have 4 coins, how many different combinations of heads and tails can you get? All heads, 1H 3T, 2H 2T, 3H 1T, all tails. 5 different possibilities. It is the same principle in the TCDD. This compound has 5 possible molecular weights. The most abundant peak would be one with 3 Cl^37 and 1 Cl^35. Add up the Mr and this would give you 322g
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    (Original post by charco)
    It's just statistics.

    Four chlorines
    Two isotopes

    How many possible (unique) combinations

    37, 37, 37, 37
    37, 37, 37, 35
    37, 37, 35, 35
    37, 35, 35, 35
    35, 35, 35, 35


    5...............................
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    (Original post by KESbian)
    Imagine you have 4 coins, how many different combinations of heads and tails can you get? All heads, 1H 3T, 2H 2T, 3H 1T, all tails. 5 different possibilities. It is the same principle in the TCDD. This compound has 5 possible molecular weights. The most abundant peak would be one with 3 Cl^37 and 1 Cl^35. Add up the Mr and this would give you 322g
    The most abundant peak would be one with 3 Cl^37 and 1 Cl^35. Add up the Mr and this would give you 322g


    I don't understand why 3 CL^37 and one cl^35?
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    (Original post by Qer)
    The most abundant peak would be one with 3 Cl^37 and 1 Cl^35. Add up the Mr and this would give you 322g


    I don't understand why 3 CL^37 and one cl^35?
    The most abundant peak wold be the one wth the most likelihood.

    The odds of a 35 are 75%, or 3/4 and the odds of a 37 Cl are 25% or 1/4

    Hence the odds for each of the following are:

    37, 37, 37, 37 = 1/256 = 0.39%
    37, 37, 37, 35 = 3/256 = 1.17 and four different ways of doing it = 4.69%
    37, 37, 35, 35 = 9/256 = 3.52% and six different ways of doing it = 21.09%
    37, 35, 35, 35 = 27/256 = 10.55% and four different ways of doing it = 42.19%
    35, 35, 35, 35 = 81/256 = 31.64%
    --------------------------------------------------- total percentage checksum = 100%

    So the most intense peak will be due to 37Cl35Cl35Cl35Cl
    With a relative mass of 322
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    (Original post by charco)
    The most abundant peak wold be the one wth the most likelihood.

    The odds of a 35 are 75%, or 3/4 and the odds of a 37 Cl are 25% or 1/4

    Hence the odds for each of the following are:

    37, 37, 37, 37 = 1/256 = 0.39%
    37, 37, 37, 35 = 3/256 = 1.17 and four different ways of doing it = 4.69%
    37, 37, 35, 35 = 9/256 = 3.52% and six different ways of doing it = 21.09%
    37, 35, 35, 35 = 27/256 = 10.55% and four different ways of doing it = 42.19%
    35, 35, 35, 35 = 81/256 = 31.64%
    --------------------------------------------------- total percentage checksum = 100%

    So the most intense peak will be due to 37Cl35Cl35Cl35Cl
    With a relative mass of 322
    thanks
    It makes sense
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    (Original post by Qer)
    thanks
    It makes sense
    Chemistry does (usually)
 
 
 
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