Compound a, c8h10, undergoes nitration to give 2 products. the 1h nmr spectrum of a shows a complex five-proton multiplet at 7.27-7.40 δ, a two-proton quartet at 2.60 δ, and a three-proton triplet at 1.25 δ. what is the structure of a?

             Compound A is Ethylbenzene.

                   The structure of Ethylbenzene was elucidated and finalized based on following facts:

1)    The presence of multiplet signal ranging from δ  7.27 to 7.40 ppm confirms the presence of aromatic protons. Also the statement says that this signal is for 5 protons indicating that the benzene ring is mono substituted.

2)   The substituted group on benzene is Ethyl because the quartet for two protons shows that two protons (-CH₂-) are coupled with a CH₃ group. Hence, the ethyl group gives one quartet and one triplet signal.

3)    The chemical reaction stated in statement is Nitration reaction. Also, the alkyl group (ethyl) is ortho-para directing in nature. Hence, it will give two products i.e. 1-Ethyl-2-nitrobenzene and 1-Ethyl-4-nitrobenzene respectively.

Attached figure gives the calculated NMR spectrum of Ethylbenzene and the chemical shifts calculated are almost near to the given values. Also, the two products formed are shown.

lithosphere and asthenosphere

explanation: no but i do not usually comment