The number of stereoisomers for a compound containing $n$ different asymmetric carbon atoms will be .............

Which of the following acids does not exhibit optical isomerism?

What are the optical isomers called that are optically active but are not mirror images of each other?

Solutions of optically active isomers rotate the plane of polarized light in a polarimeter. Match the following columns $(I)$ with $(II), (III)$,and $(IV)$ correctly:

$(I)$ Optical Activity	$(II)$ Form	$(III)$ Sign	$(IV)$ Rotation
$(A)$ Dextrorotatory	$d$	$(+)$	Right
$(B)$ Laevorotatory	$l$	$(-)$	Left
$(C)$ Optically Inactive (Racemic)	$dl$	$(\pm)$	Zero rotation

Which of the following properties is $NOT$ identical for enantiomers?

The number of stereoisomers for the compound $CH_3-CHBr-CHBr-COOH$ is ......... .