DAT Organic Chemistry: Stereochemistry 2

Question 1

How many stereoisomers are possible for a molecule with 3 stereocenters and no internal symmetry?

Accepted Answer

8

Answer

6

Answer

9

Answer

4

Question 2

Two compounds are enantiomers. Which property differs between them?

Accepted Answer

Direction of plane-polarized light rotation

Answer

Boiling point

Answer

Density

Answer

Melting point

Question 3

A meso compound is best described as:

Accepted Answer

Achiral despite having stereocenters

Answer

Optically active with no stereocenters

Answer

A pair of enantiomers

Answer

A constitutional isomer

Question 4

What is the relationship between (2R,3R) and (2S,3R) of the same molecule?

Accepted Answer

Diastereomers

Answer

Enantiomers

Answer

Identical

Answer

Constitutional isomers

Question 5

In assigning R/S, which atom gets highest priority?

Accepted Answer

Highest atomic number

Answer

Smallest atomic radius

Answer

Highest electronegativity

Answer

Lowest mass

Question 6

A racemic mixture has what observed optical rotation?

Accepted Answer

Zero

Answer

Strongly positive

Answer

Strongly negative

Answer

Equal to one enantiomer

Question 7

Geometric (cis/trans) isomerism requires:

Accepted Answer

Restricted rotation such as a double bond or ring

Answer

A tetrahedral carbon

Answer

An sp carbon

Answer

A lone pair