Above is the structure of 2,3,4 - trichloropentane. Numbering can be done from any side because it does not make any difference.
Chiral carbon is a carbon atom that is attached to four different types of atoms or groups of atoms. Hence, C−1 and C−5 can't be chiral as they are connected to 3 hydrogen atoms. C−3 is attached to two same groups on both sides, so it is also not a chiral carbon. C−2 and C−4 are connected to 4 different groups, hence both are chiral carbon.
