BLOCK ONE

Question 1

a single bond is made of a

Answer 1

sigma bond

Question 2

a double bond is made of

Answer 2

one sigma bond and one pi bond

Question 3

a triple bond is made of

Answer 3

one sigma bond and two pi bonds

Question 4

what does not appear in the DBE formula

Answer 4

oxygen

Question 5

what are constitutional isomers

Answer 5

have the same molecular formula, different atom to atom bonding sequence

Question 6

what are conformational isomers

Answer 6

have the same molecular formula, same atom to atom bonding sequence but the arrangement in space differs and it can interconvert by rotation about a single bond

Question 7

what happens to groups in ring flip

Answer 7

all axial groups&raquo_space;> equatorial
all equatorial groups&raquo_space;> axial
but up stays up and down stays down

Question 8

the favoured conformer has the largest atom/group in the

Answer 8

equatorial position

Question 9

what are configurational isomers

Answer 9

same molecular formula, same atom to atom bonding sequence but the arrangement in space differs and they can only be converted by breaking and reforming a covalent bond

Question 10

what are the two classes of configurational isomers

Answer 10

enantiomers and diastereomers

Question 11

what are enantiomers

Answer 11

chiral and non-superimposable mirror images

Question 12

what are diastereomers

Answer 12

chiral, non-superimposable and not mirror images (e/z, cis/trans etc)

Question 13

state increasing priority of main elements

Answer 13

H < C < N < O < F < Cl < Br < I

Question 14

if two higher priority on the same side of the double bond, what configuration?

Answer 14

Z

Question 15

if two higher priority on opposite sides of the double bond, what configuration?

Answer 15

E

Question 16

when can enantiomers exist?

Answer 16

when you have sp3 carbon with 4 different groups attached

Question 17

what is an achiral molecule

Answer 17

doesn’t have a carbon with four different groups attached

Question 18

how can you differentiate between the two enantiomers?

Answer 18

through the direction in which they rotate plane polarised light

Question 19

what is a racemic mixture

Answer 19

a mixture of equal amounts of the two enantiomers

Question 20

how do racemic mixtures rotate light

Answer 20

equally in both directions and thus show an overall rotation of zero

Question 21

is clockwise R or S

Answer 21

R

Question 22

is anticlockwise R or S

Answer 22

S

Question 23

if a molecule has high polarity it is

Answer 23

more water-soluble and is hydrophilic

Question 24

if a molecule has low polarity it is

Answer 24

more lipid-soluble and lipophilic

Question 25

electron-rich are...

Answer 25

nucleophiles

Question 26

electron-deficient are...

Answer 26

electrophiles

Question 27

nucelophiles have...

Answer 27

neutral lone pairs, negative charge, pi bonds or negative atom of polar bond

Question 28

electrophiles have...

Answer 28

positive charge or positive atom of polar bond

Question 29

difference between SN1 and SN2

Answer 29

``` SN1 = bond breaking and then bond forming SN2 = bond breaking/forming is simultaneous ```