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Mass spectrometry question help!

020200

Hi,

Can someone please help me on this question? I have done part a) and most of part b) correctly but was unsure on how to answer the the last bit of part b) where it says "Sometimes the mass spectrum... occurrence of this peak". Can someone please explain how to answer this bit? Unsure on what the mark scheme means as well...

Thanks!

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Reply 1

Eruthien420

I do A-level chem n I've never seen anything like this wtf.

Reply 2

eav_3508

I think the answer is that a few of the krypton atoms will be ionised twice, meaning they will be 2+ ions rather than 1+ ions. This will double the speed of these ions and therefore halve the time taken for them to reach the detector, resulting in the mass/charge ratio of the 2+ ions being half that of the 1+ ions. Hope this makes sense 😊