Explanation

(b)
(A)$CH_{3} - CH - CH_{2}CH_{3}$
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Cl
One asymmetric carbon atom, forms$\ d$, and $l -$optical and isomers.
(b) Two asymmetric carbon atoms, forms $d$, $l$ and $meso$ forms
[image:12_image291.emf]
$Meso$ due to internal compensation
[image:12_image292.emf]
Two asymmetric carbon atoms but does not have symmetry. Hence, $meso$ form is not formed.
[image:12_image293.emf]
One asymmetric carbon atom, $meso$ form is not formed.