Help please it’s present yield and please leave an explanation too

Iam in desperate need of with this !

For the following dehydrohalogenation (e2) reaction, draw the zaitsev product(s) resulting from elimination involving c3–c4 (i.e., the carbon atoms depicted with stereobonds). show the product stereochemistry clearly. if there is more than one organic product, both products may be drawn in the same box. ignore elimination involving c3 or c4 and any carbon atom other than c4 or c3.

What is the mass defect of a mole of nuclei with 1.8 x 10^15 j/mol binding energy?