Isomerism and Stereochemistry

Question 1

same chemical formula but differ in chemical and physical properties

Answer 1

isomerism

Question 2

study of the different spatial arrangements of atoms in molecules

Answer 2

stereochemistry

Question 3

stereochemistry is also known as __ __

Answer 3

3D chemistry

Question 4

stereo means __

Answer 4

three-dimensional

Question 5

one of the reasons why there is a huge array of different organic compounds that exist

Answer 5

isomers

Question 6

Two classifications of isomers

Answer 6

1. Structural Isomerism
2. Stereochemical Isomerism

Question 7

Three types of Structural Isomerism

Answer 7

1. Skeletal Isomerism
2. Positional Isomerism
3. Functional Isomerism

Question 8

Two types of Stereochemical Isomerism

Answer 8

1. Configurational Isomers
2. Conformational Isomers

Question 9

Two types of Configurational Isomers

Answer 9

1. Geometric Isomerism
2. Optical Isomerism

Question 10

Geometric Isomerism

Answer 10

Cis-Trans Isomerism in Cyclic Compounds

Question 11

Two types of Optical Isomerism

Answer 11

1. Diastereomers
2. Enantiomerism

Question 12

Two types of Enantiomerism

Answer 12

1. Fischer Projection
2. Chiral Center

Question 13

Structural Isomerism or __ __ in IUPAC nomenclature

Answer 13

Constitutional isomerism

Question 14

occurs when two or more compounds have the same molecular formula but different structural formula due to different arrangements of how atoms are connected

Answer 14

Structural Isomerism

Question 15

skeletal isomerism is also called __ __

Answer 15

chain isomerism

Question 16

differ only in the arrangement of atoms in the carbon skeleton

Answer 16

skeletal isomerism

Question 17

dimethylbenzene is knwon collectively as __

Answer 17

xylenes

Question 18

difference with the position of the same functional group in a carbon chain

Answer 18

positional isomerism

Question 19

same molecular formula, but different functional groups

Answer 19

functional isomerism

Question 20

same molecular formula and sequence of bonded atoms, but differ in the three-dimensional orientations of their atoms in space

Answer 20

1. Geometric Isomerism
2. Optical Isomerism

Question 21

occurs when a compound contains a double bond, and has two different atoms or groups that are attached to each of the carbons in the double bond

Answer 21

geometric isomerism

Question 22

formed when two hydrogen are on the same side (top or bottom) of the double bond

Answer 22

cis isomers

Question 23

occur when two hydrogens are on opposite sides

Answer 23

trans isomers

Question 24

• non-interconvertable
• interconversion must need bond breaking and making

Answer 24

configurational isomers

Question 25

stereoisomers that cannot be converted into one another by rotating the molecule around a single bond

Answer 25

configurational isomers

Question 26

ability of a chiral molecule to rotate the plane of plane-polarised light

Answer 26

optical activity

Question 27

used to measure plane of plane-polarised light

Answer 27

polarimeter

Question 28

simple polarimeter consists of:

Answer 28

- light source - polarising lens - sample tube - analysing lens

Question 29

stereoisomers that are non-superimposable mirror images of one another

Answer 29

enantiomers

Question 30

structural basis of enantiomerism

Answer 30

chirality

Question 31

any molecule that is superimposable on its mirror image

Answer 31

achiral

Question 32

tetrahedral atom in a molecule bearing four different ligands, with lone pairs, if any, treated as ligands (or substituents)

Answer 32

chiral center

Question 33

in determining chiral center, keep going down the __

Answer 33

chain

Question 34

a way to represent three-dimensional molecules in two dimensions

Answer 34

fischer projections

Question 35

two-step procedure to determine absolute configuration of a chiral center in Fischer projection

Answer 35

1. Assign priority numbers to four lgans on chiral center 2. trace three highest-priority ligands

Question 36

partial stereoisomers that have at least two stereocenters and differ in configuration at some, but not all, of these stereocenters

Answer 36

diastereomers

Question 37

- non-mirror image stereomers - do not have a relationship of symmetry or chirality between them

Answer 37

diastereomers

Question 38

to identify a diastereomer of a chiral compound, it must only...

Answer 38

have different configurations at some stereocenters but not all

Question 39

diastereomers that are optically inactive due to their symmetry

Answer 39

meso compounds

Question 40

two identical substituents are present on the same side of a compound

Answer 40

cis configuration

Question 41

two identical substituents are present on the opposite side of a compound

Answer 41

trans configuration