How many optically active isomers of `2,3-`dibromosuccinic acid are there?

How many optically active isomers of 2,3-Dichlorobutandioic acid are possible ?

How many optically active isomers are possible for

The number of optical active isomers of 2,4 dibromobutane are

How many optically active stereoisomers are possible for lactic acid ?

Optically active isomers are also called:

How many structural isomers and stereoisomers of bromopiperidine are possible? b. How many stereoisomers of 4-chlorocyclo-hexane are possible? c. How many optically active and inactive isomers of 2,3,4,5 - tetrachloroadipic acid are possible? d. How many meso diastereomers of C_(6)H_(12)Br_(2) are possible e. How many optically active inactive isomers of 1,2,3- trimethylcyclohexane are possible?