Answer:
In the 13C NMR (Nuclear Magnetic Resonance) spectrum of ethylbenzene, you would expect to see a total of 5 signals.
Step-by-step explanation:
Ethylbenzene (C8H10) contains 8 carbon atoms (C) in its structure. However, not all carbon atoms will give distinct signals in the 13C NMR spectrum due to the concept of symmetry and chemical environment.
The carbon atoms in ethylbenzene can be divided into different types based on their chemical environment. There are:
Two types of methyl carbons (CH3) attached to the ethyl group.
Three types of methylene carbons (CH2) in the ethyl group.
One type of methylene carbon (CH2) attached to the benzene ring.
Two types of quaternary carbon (C) atoms in the benzene ring (which are equivalent due to symmetry).
Each distinct chemical environment will produce a separate signal in the 13C NMR spectrum. Hence, you would observe a total of 5 signals in the 13C NMR spectrum of ethylbenzene.