Answer :
Answer:
Part a: The IR spectrum is not sufficient due to the similar radical group presence in both product and reactants.
Part b: Mass Spectrum data is required in addition to the IR data for confirming the presence of recrystallized product.
Part c: The additional data is consistent with the expectations as the data is in support of that.
Explanation:
Part a
Acetanilide has a characteristic IR peak at around 3100-3200 cm^-1 (N-H Stretching) and 1500-1680 cm^-1 (C=O Stretching). Since a similar radical group ([tex]NHCOCH_3[/tex]) is present in the 4-bromoacetanilide, thus it is difficult to affirm the presence of the product solely on the basis of IR spectrum.
Part b
Mass Spectral data will affirm the presence of recrystallized product with certainty.
Part c
4-bromoacetanilide will have [tex]M^+[/tex] peak at two points (213 & 215) corresponding to the two Bromine isotopes (79 & 81).
Also parent peak at 171 ([tex]M^+[/tex]=43) will be in 49:51 due to presence of Bromine atoms.