Statement I:
When 3-phenylpropene reacts with HBr, protonation of the alkene occurs to form a secondary carbocation.
C6H5−CH2−CH=CH2+H+→C6H5−CH2−CH+−CH3
This secondary carbocation undergoes a 1,2-hydride shift to form a more stable, resonance-stabilized benzylic carbocation.
C6H5−CH2−CH+−CH3→C6H5−CH+−CH2−CH3
The bromide ion then attacks this benzylic carbocation to form the major product, 1-bromo-1-phenylpropane.
C6H5−CH+−CH2−CH3+Br−→C6H5−CH(Br)−CH2−CH3
The carbon atom bonded to the bromine is attached to four different groups: a phenyl group (−C6H5), an ethyl group (−CH2CH3), a hydrogen atom (−H), and a bromine atom (−Br). Thus, it is a chiral carbon. The product is a secondary alkyl bromide. Therefore, Statement I is true.
Statement II:
The Sandmeyer reaction involves treating a diazonium salt with Cu(I) salts (CuCl, CuBr, CuCN) to prepare aryl chlorides, aryl bromides, and aryl cyanides, respectively.
The Gattermann reaction involves treating a diazonium salt with copper powder (Cu) and halogen acids (HCl, HBr) to prepare aryl chlorides and aryl bromides. Aryl cyanides are not prepared using the Gattermann reaction. Therefore, Statement II is false.
Conclusion: Statement I is true but Statement II is false.
Answer: Statement I is true but Statement II is false