(i) A molecule is said to be chiral when mirror image are non-superimpossible. For chirality of a molecule there should be no element of symmetry if a molecule contains only one chiral carbon atom , it is always chiral e.g., Lactic acid.
non-Superimpossible mirror image enantiomers .
(ii) `CH_(3)underset(Cl)underset(|)(-)CH-CH_(2)-CH_(3)`
undergoes hydrolysis more readily by `S_(N)I` mechanism because it gives more stable `2^(@)` carbocation `(CH_(3)-underset(o+)(C)H-CH_(2)-CH_(3))`
(iii)
reacts faster due to low e-I bond energy.