Question

CNMR spectra 2,2,4-trimethylpentane.

A) 5 signals
B) 6 signals
C) 7 signals
D) 8 signals

Answer 1

For 2,2,4-trimethylpentane, the carbon-13 NMR spectrum would exhibit 6 unique signals, corresponding to the six distinct carbon environments in the molecule.

Step-by-step explanation:

The student is asking about the number of different signals that would appear in the carbon-13 NMR (CNMR) spectrum for the molecule 2,2,4-trimethylpentane. To answer this question, one must consider the symmetry and the unique environments of the carbon atoms within the molecule. 2,2,4-trimethylpentane has three types of methyl groups (all carbons are quaternary or methyl carbons, no CH or CH2 groups), a quaternary carbon at the 3-position, and two methylene groups (the 1 and 5 positions are equivalent due to symmetry). Therefore, the correct answer is B) 6 signals, one for each unique carbon environment.