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# Help answer this question please :) watch

1. Hi can anybody please post a step by step reply as to how to answer this question:

The mass spectrum of CH3Br contains two molecular ion peaks of equal abundance with m/z values of 94 and 96. Deduce the number of molecular ion peaks in the spectrum of the compound CH2Br2. Give their relative abundances and the m/z value of the molecular ion peaks.

Thank you xx
2. (Original post by xgoldenx)
Hi can anybody please post a step by step reply as to how to answer this question:

The mass spectrum of CH3Br contains two molecular ion peaks of equal abundance with m/z values of 94 and 96. Deduce the number of molecular ion peaks in the spectrum of the compound CH2Br2. Give their relative abundances and the m/z value of the molecular ion peaks.

Thank you xx
Basically the question is telling you that bromine exists as two isotopes 79-Br and 81-Br

If there are two bromine atoms in the molecule how many different combinations of bromine atoms are there possible.

As the probability of 79-Br and 81-Br are equal, work out the relative probability of each combination occurring. (you can treat them like two coins, heads and tails)
3. (Original post by charco)
Basically the question is telling you that bromine exists as two isotopes 79-Br and 81-Br

If there are two bromine atoms in the molecule how many different combinations of bromine atoms are there possible.

As the probability of 79-Br and 81-Br are equal, work out the relative probability of each combination occurring. (you can treat them like two coins, heads and tails)
I always come to these kinds of threads thinking I'll be able to answer the question really well, and then I see someone has already posted an answer that's a lot clearer and better explained than mine would've been.

Well done sir/ madam.
4. (Original post by I'mBadAtMaths)
I always come to these kinds of threads thinking I'll be able to answer the question really well, and then I see someone has already posted an answer that's a lot clearer and better explained than mine would've been.

Well done sir/ madam.
especially when that someone is charco...

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