Question

Draw the mechanism, including the intermediate bromonium ion, generated in the bromination of trans-2-pentene. show each step separately and show all electron movement. clearly indicate the stereochemistry of the products and label each chiral center as r or s.

Answer 1

Addition of Bromine to trans-2-pentene give the following product:
Step wise reaction involving a bromonium ion intermediate and the addition is trans- or anti-addition as follow:
Check the attached picture.
also the stereo chemistry of products [Optically active compound]  and R, S is is mentioned