Answer:
1-bromo-6-methylheptane : X
2-chloro-6-methylheptane: Y
Explanation:
A chiral compound is one which has a carbon with all four groups different.
Given:
Compound X is Achiral
Compound Y is chiral
Compound X gives single alkene on elimination : Z
Compound Y gives mixture of alkenes
Z on hydrogenation gives 2-methylheptane.
So the alkene must have carbon chain arrangement similar to 2-methylheptane and so the compound X and Y.
Based on the information the possible compounds are:
1-bromo-6-methylheptane : X
2-chloro-6-methylheptane: Y
The structures are shown in the figure.