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Qer
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- 14-03-2018 18:39
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Qer
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- 14-03-2018 18:43
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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- 14-03-2018 18:49
Last edited by Qer; 14-03-2018 at 18:50. -
charco
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- 14-03-2018 18:52
(Original post by Qer)
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
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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- 14-03-2018 19:04
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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- 14-03-2018 22:27
(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............................... -
Qer
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- 14-03-2018 22:34
(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
I don't understand why 3 CL^37 and one cl^35? -
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- 15-03-2018 09:14
(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 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 -
Qer
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- 15-03-2018 17:18
(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
It makes sense -
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- 15-03-2018 19:29
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