[ariaxxx]

How do I go about this question?

Principle fragmentation of the molecular ion of 2,3-dimethyl-3-pentanol would be expected to produce how many peaks in the mass spectrum? 

In other words, how many observable peaks does the molecular ion itself produce when it fragments (we’re not concerned here with subsequent fragmentation of smaller fragments, nor with the molecular ion peak itself). 


I thought you would just count the number of distinct bonds you could fragment and so I got 6 but apparently that's wrong. How do you do this??

[kriggy]

Well usualy the weakest bonds fragment so I would guess it would break around the OH bond. Do you know what is the correct answer?

[ariaxxx]

So which ones are the weakest bonds then? And the answer is 4.

Also for this other one it asks to give the weight of the lightest fragment for 3-chloro-3-methylhexane. Where would that fragment then???

[Furanone]

This should give you some hints:

http://webbook.nist.gov/cgi/cbook.cgi?ID=C595415&Units=SI&Mask=200#Mass-Spec

Look at the chemical structure and see where it could fragment to create smaller pieces of the right MW that you see as the highest m/z peaks: