# Chemistry - Mass Spec question help AQA

Watch
Announcements
#1
Can anyone explain question 11 iv please?
(http://pmt.physicsandmathstutor.com/...0Structure.pdf)
0
4 years ago
#2
(Original post by J-ved)
Can anyone explain question 11 iv please?
(http://pmt.physicsandmathstutor.com/...0Structure.pdf)

The m/z ratio of the 36S+ ion is 36

So one of those Ge isotopes has an ion that can give that same m/z (the question says "indistinguishable", so basically the same peak as the S ion)

It's likely that the Ge ion will have a 2+ charge. To get from 70-74 to 36, you can't just have a 1+ charged ion.

So playing w/ some numbers, you find that if the 72Ge isotope had a 72Ge2+ ion, it would also have m/z = 36
1
#3
(Original post by telepathicnine)
The m/z ratio of the 36S+ ion is 36

So one of those Ge isotopes has an ion that can give that same m/z (the question says "indistinguishable", so basically the same peak as the S ion)

It's likely that the Ge ion will have a 2+ charge. To get from 70-74 to 36, you can't just have a 1+ charged ion.

So playing w/ some numbers, you find that if the 72Ge isotope had a 72Ge2+ ion, it would also have m/z = 36
I see, thank you!
0
X

new posts
Back
to top
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### Poll

Join the discussion

#### Do you think receiving Teacher Assessed Grades will impact your future?

I'm worried it will negatively impact me getting into university/college (191)
43.81%
I'm worried that I’m not academically prepared for the next stage in my educational journey (49)
11.24%
I'm worried it will impact my future career (34)
7.8%
I'm worried that my grades will be seen as ‘lesser’ because I didn’t take exams (91)
20.87%
I don’t think that receiving these grades will impact my future (46)
10.55%
I think that receiving these grades will affect me in another way (let us know in the discussion!) (25)
5.73%