Answer:
C5H11Cl with the Cl group attached to the chiral carbon
Explanation:
radical chlorination is given by:
C5H12 + Cl2 → C5H11Cl + HCl
Such reactions are unselective, the product could either 1-chloropentanes, 2-chloropentanes, or 3-chloropentanes, all with the same molecular formula C5H11Cl but different structure(depending on on the carbon the chlorine is attached)
1-chloropentanes has its Cl group attached to a primary carbon
2-chloropentanes has its Cl group attached to a second carbon
3-chloropentanes has its Cl group attached to a third carbon
SN2 reactions occurs fastest on the primary carbon(chiral) which. Therefore Y is 1-chloropentane which has its Cl group attached to a primary carbon with no beta-branching will proceed the fastest.