Question

discuss how each would act in a polarimeter (pure enantiomers, racemic mixtures, meso compounds

Answer 1

polarimeter is used to know a compound is optically active or not.

if a molecule rotates the plane polarised light, such molecule is said to be optically active.

So if pure eneantiomers are taken in a polarimeter, they can rotate the plane polarised light.

if racemix mixture (equimolar mixture of enantiomers) is taken, it doen't rotate the plane polarised light. so it is optically inactive.

if meso compounds are taken, they are also not roates the plane polarised light due to presence of plane of symmetry. so it is optically inactive