lecture 5: chirality

Question 1

BLANK objects are nonsuperimposable mirror images

Answer 1

chiral objects

Question 2

blank objetcs are mirror images which are superimposable

Answer 2

achiral objects

Question 3

what are chiral objecst

Answer 3

non superimposable mirror images

Question 4

what are achiral objects

Answer 4

mirror images which are superimposable

Question 5

give example of chiral objects

Answer 5

hands, ears, feet

Question 6

give examples of achiral objects

Answer 6

cup, chair, pencil

Question 7

what are constitutional isomers

Answer 7

same mol formula diff connectivity

Question 8

what are stereoisomers

Answer 8

same connectivity same molcular formula but different arrangements of atoms in 3d space

same connectivtiy but different 3d isomers

Question 9

what are the 2 catergoes of steroisomers

Answer 9

enantiomers

diasteriomers

Question 10

what are enantiomers

Answer 10

stereoisomers that are NON superimposable mirror images

Question 11

what are diasteriomets

Answer 11

stereosiomers that are non-superimposabl, none mirror images

Question 12

which are stereoisomers that are NON superimposable mirror images

Answer 12

enamtiomers

Question 13

which are stereosiomers that are non-superimposabl, none mirror images

Answer 13

diastomeriomers

Question 14

a chiral compound and its mirror image is a diastereomer or enenatiomer

Answer 14

enantiomer

Question 15

true or false: enantimoers can only occur for chiral molucles

Answer 15

true

Question 16

what are isomers

Answer 16

same mol formula but diff compound

Question 17

what is an assymetric center

Answer 17

c bound to 4 diff substituents

Question 18

isomers with assymetric centers are what shape

Answer 18

tetrahedral

Question 19

cis trans isomers refer to spatial orietnance about what

Answer 19

about a double bond or a ring

Question 20

true or false: enantiomer is a non superimposable mirror image

Answer 20

true

Question 21

true or false: enantiomers are trigonal planar with 3 diff groups

Answer 21

false, they are tetrahydral with 4 diff groupes resulting in 2 possible configurations

Question 22

cis trans isomers are non superimposable non mirror images, therefore that makes them what type of isomer

Answer 22

diastermioer

Question 23

what is a chiral center

Answer 23

a tetrahedral carbon bonded to 4 different groups (sp3 hybridized)

Question 24

changing conf requires what

Answer 24

breaking bonds

Question 25

changing comformation requires what

Answer 25

rotating bonds

Question 26

true or false: molcuels with only 1 chiral center are chiral

Answer 26

true

Question 27

compounds with one chiral center exist as two different steroisomrs called...

Answer 27

enantiomers

Question 28

true or false: a chiral center is not always possible for a single tetrahedral atoom (sp3 hybrid) with 4 diff cgroups attached

Answer 28

false

Question 29

what is a stereogenic center

Answer 29

any atom at which the interchange of two groups produced a stereoisomer

Question 30

true or false; all sterocenters are chiral centers

Answer 30

false (ex: sp2 carbons)

Question 31

what is the biological imporatnt of chirality

Answer 31

body can distinguish between enantiomers (specific bonding sites) and is only favouranble in 1 way

Question 32

true or false: a compound can still be chiral with an internal plane of symmetry

Answer 32

false, it will not be chiral it is possese an internal plane of symmetry

Question 33

what are the 4 steps for naming enantiomers (chiral center)

Answer 33

1) each group is assignmend priority according to atmic number 2) if two identical, next bond is looked at (double bond coutns as two) 3) orient molcule so that low priority is in the back 4) trance clock (r) or CCW (S)

Question 34

true or false: chiral molecules have no optical activtiy

Answer 34

false, they do

Question 35

what molecules are optically inactive

Answer 35

achiral

Question 36

what are the conditions for something to be optically activtiy

Answer 36

1) must be chrial | 2) one enatiomer must be present in excess (or just cancel each otehr out)

Question 37

what do enantiomers do to polar plane light

Answer 37

cause equal rotation of the plane of polarixation but in opposive directions

Question 38

if something is + that means it does what to light

Answer 38

rotates it CW

Question 39

if something is - that does what to light

Answer 39

rotates it CCW

Question 40

what happens if you have exactly the same amount of enatiomers are use plane polarized loght

Answer 40

since there are equal concentrations, you will get a racemic mixture and it will be optically inacvity (cancel each other out)

Question 41

does something need to be optically pure solution to have optical acivtiy

Answer 41

no as long as one of the enantiomers is in excess

Question 42

what is an optically pure solition

Answer 42

a solution containing one 1 enantioner

Question 43

true or false: reaction of 2 achiral molcules leadss to an achiral molecule

Answer 43

false, can sometimes lead to chiral products

Question 44

what is the formula for finding all thepossible configurations for molecules with 2 chiral centers

Answer 44

2 ^ n where n is number of chiral centers

Question 45

what is the trick for finding different chiral compunds with 2 chriality

Answer 45

RR SS RS SR (flip both simul, flip one side, flip other) =always keep ones on the chain the same

Question 46

true or false: enantiomers are mirror images of each other

Answer 46

true

Question 47

true or false: enatimiors have opposite and unequal rotation of polarized light

Answer 47

false, equal

Question 48

do aenatiomers have same or diff physical properties

Answer 48

same

Question 49

are diasteriomers mirror images of each other

Answer 49

no

Question 50

what is the relationship between diasteriomers are polarized light?

Answer 50

no direct correleation

Question 51

do diasteriomers have same or diff physical properties

Answer 51

very diff

Question 52

true or false: a strucuter with 2 chriality centers always has 4 isomers

Answer 52

false, sometimes only has three because of meso compounds

Question 53

are all molecules with chriral centers considered chiral compounds

Answer 53

no they can be achoral