April 14, 2021, 06:50:38 PM
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### Topic: Mass Spectrum of O2  (Read 165 times)

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#### Flyingtaka

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##### Mass Spectrum of O2
« on: February 23, 2021, 04:35:00 AM »
Hey,
So I have a question which states an unknown diatomic element was analysed using mas spectrometry.
Peaks are produced at 32 and 16 (nothing else) with 32 being the base peak with a relative abundance of 100.

I am then asked to state the Mr of this unknown diatomic element based on the mass spectrum.

"The base peak on the mass spectrum above is 32, it also has the largest m/z value which means it is the largest ion going through the mass spectrometer. The relative molecular mass of element A must therefore be 32"

Is this correct? I feel like the Mr of the unknown ELEMENT would actually be 16, because 32 would be the Mr of the molecule (O2) where as 16 would be the weight of O

Thanks!
Also I hope this is in the right forum, I am based in the UK so we have different grading but I guessed it would fit in here.

#### AWK

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##### Re: Mass Spectrum of O2
« Reply #1 on: February 23, 2021, 04:43:07 AM »
AWK

#### Flyingtaka

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##### Re: Mass Spectrum of O2
« Reply #2 on: February 23, 2021, 04:49:33 AM »
Thank you, just to make sure I fully understand it, has an Mr of 32 because it is the largest ion going through the mass spectrometer and the peak at 16 is just where O2 has broken into oxygen ions. I wouldn't factor in the peak at 16 when it comes to calculating the Mr?

#### Borek

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##### Re: Mass Spectrum of O2
« Reply #3 on: February 23, 2021, 06:56:04 AM »
I feel like the Mr of the unknown ELEMENT would actually be 16, because 32 would be the Mr of the molecule (O2)

Yes.
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