Question

What is the structural formula and name of the major productsCh3ch2ch2ch=ch+hcl

Answer 1

We can't draw diagrams or structural formula on this site. Follow Markonikov's rule . Note that if you want this to be 1-pentene you must add a H atom to the terminal C on the right.
CH3CH2CH2CH=CH2 + HCl ==> CH3CH2CH2CHClCH3 which I would call 2-chloropentane