The Student Room Group

NMR Spectroscopy:Help!

In relation to NMR Spectroscopy:-

A compound of the formula C5H12 only shows one peak. Suggest a structural formula for this isomer?

The answers say that is cyclopentane, but how could this be, i thought cyclopentane had the formula C5H10, or am i just being stupid!?

This seems like a really really easy question, but i am just really confused!
I would be very greatful if anyone can help!
Thank You :redface:
Reply 1
It's strutural formular is C(CH3)4 due to all the CH3 groups have the same condition in this compound, so they have the same position in NMR spectro, which gives you only high peak of 4 (CH3) groups.
Reply 2
Sheilz001
In relation to NMR Spectroscopy:-

A compound of the formula C5H12 only shows one peak. Suggest a structural formula for this isomer?

The answers say that is cyclopentane, but how could this be, i thought cyclopentane had the formula C5H10, or am i just being stupid!?

This seems like a really really easy question, but i am just really confused!
I would be very greatful if anyone can help!
Thank You :redface:

You are right.
To me it looks like it has to be 2,2-dimethylpropane (ie 4 methyl groups all coming off one carbon).

All the H's in this are identical so you only get one peak.
Reply 3
Thank You! :smile: