Exam 1 Flashcards
Lectures 1-14 (78 cards)
1
Q
induction - distance
A
the closer the electronegative atom is to the hydrogen, the stronger the acid, the lower the pka
2
Q
induction - electronegativity
A
the more electronegative atom is the stronger acid, lower pka
3
Q
induction - additive
A
the more # of electronegative atoms = more acidic = lower pka
4
Q
orbital
A
charge on atoms w/ double or triple bonds are most stable CB, so lower pka
sp
5
Q
Which side does equilbirum favor?
A
- weaker acid/weaker base (will be on same side)
- more stable acid/base
6
Q
pH>pka
A
deprotonated
7
Q
pH<pka
A
protonated
8
Q
weaker acid
A
stronger C.B
9
Q
henderson hasselbalch
A
pH-pka=-log([A-]/[HA])
* base/acid
10
Q
naming compounds
A
- find parent chain - if tie then choose one with most substituents
- number the parent chain
- lowest sub on lowest numbered C
- tie - 2nd substituent on lowest numbered C
- tie again - alphabetically - name parent chain and subsitutients
- don’t forget cyclo
- don’t forget prefix ex. di, tri
- alphabetical order (to break tie if needed) and when putting name together
11
Q
energy of H-H eclipsed
A
4 kj/mol
12
Q
most stable chair structure
A
biggest groups = equatorial
12
Q
line wedge to chair
dashes
solids
A
dashes-down
solids-up
13
Q
stereoisomers
A
2^n
14
Q
boiling point priorities
A
- h bonding
- mass
- branching
15
Q
vinyl vs allyl
A
vinyl: atoms on C of alkene
allyl: atoms adjacent to C of alkene
16
Q
resonance importance
A
- complete octet
- fewest F.C
- negative charge on more E.N atom, positive charge on least E.N atom
17
Q
boiling point
A
higher boiling point
1. can H-bond
2. higher mass
3. less branching
17
Q
hydrogen bonding
A
between H and FON
* H attached to FON in 1 molecule
* FON in the other molecule need lone pair(s)
18
Q
acyl halide
A
keytone but replace one R with X
19
Q
aldehyde
A
keytone but replace one R and H
20
Q
ester
A
keytone but replace one R with OR
21
Q
resonance
A
- lose electron = add 1 to charge
- gain electron = substract
22
Q
resonance - carbocations
A
allylic carbocation
1. pi bond to sigma bond with carbocation
lone pair adjacent
1. lone pair to sigma bond
23
resonance - allylic lone pair
1. lone pair to sigma bond
2. pi bond to carbon
24
resonance -
pi bond to lone pair when more EN atom present
25
resonance - ring
rotate each pi bond when there's a benzene
26
common examples of resonance on test
allylic lone pair resonance 2x, 1 after the other
27
rule for drawing bond line structures
if hydrogen next to non CH, you have to draw it
28
acids and bases
1. identify acid and base
- acid donates protons so often positive or neutral
2. draw arrow from lone pair on base to proton of acid
3. draw 2nd arrow from X-H bond to atom connected to proton
4. draw conjugate acid and base
* just remember electrons to acid
29
base to CA
* proton
* lose a electron pair
* add 1 to charge
30
acid to CB
* lose a proton
* gain an electron pair
* -1 to charge
31
ARIO (stability of negative charge) - atom
* same group - size, bigger the size = more stable
* same period - E.N, more E.N. = more stable
32
acid to CB
lose H
33
more stable CB = stronger acid = lower pka
34
ARIO - resonance
has resonance = more stable
35
what does equilbrium favor
weaker acid or weaker base (on same side)
* more stable side
36
how to pick an acid to protonate a molecule
acid has to have pka lower than pka of the molecule
37
acidity
willingness to donate protons
38
how to pick a base to deprotonate a molecule
base has to have pka higher than pka of molecule
39
henderson hasselbalch
ph-pka=log([A-]/[AH])
40
consitutional isomers
different connectivity of atoms, same M.F
41
newman projections
looking straight down C-C bond
42
staggared angle
anti (180) or gauche (60)
43
eclipsed
0 degrees
44
is staggared or eclipsed more stable
staggared
45
energy for H-H in eclipse
4 kj/mol
46
gauche degree
60 or 300
47
drawing chair confirmation 8 rules
* up is still up
* down is still down
* eq → ax
* ax → eq
* move by 1 C
* alternate up and down for every C
* eq is parallel to opposite
* each C has 1 ax, 1 eq
48
axial
vertical
49
equatorial
not vertical
50
which chair conformation is the most stable
when bigger group (ex. methyl) is equatorial
51
chair structure - solid vs dashed wedges
solid - up
dashed - down
52
cis
same side of ring - both into or both out of page
53
trans
different sides of the ring - one into page and one substituent out of page
54
if you have substituents on same numbered of C...
bigger groups go on lower numbered Cs
55
stereoisomers
same M.F. and connectivity, different spacial arrangment
ex. enantiomers, diastereomers
56
constitutional isomers
same M.F., different connectivity
57
how to check if chair structures are identical, stereoisomers, or consitutional isomers
draw the cyclohexane of it
- down = into the page
- up = out of the page
58
superimposable meaning
asymmetric meaning
superimposable = identical
asymmetric = not symmetrical
59
when is a molecule chiral
when C is attached to 4 different subsituents
60
when is a cyclohexane chiral
if 1 path around the ring is different than the other path
61
enantiomer
its mirror image is not identical to it
- refers to the mirror image
- only a chircal center can have it
62
how to draw an enantiomer
flip wedges and dashes
63
how to assign R and S
1. find chircal center
2. number substituents based on priority
- H is usually 4
- look at atomic number, higher atomic number = higher priority
- priority is based on first point of different so keep going out until there's a difference
3. draw arrow from 1 to 3
64
enantiomer special case
if you mirror a molecule with no wedges or dashes (it's just in the plane), then it's identical, not enantiomers
65
bulkiness - methyl vs halogens
methyl is bulkier than F, Br, Cl; methyl has similart bulkiness compared to I
66
how to know which way to turn from newman projection to bond line
the eyeball
67
chair projection note
if you cut chain in half horizontally, for AXIAL
- 3 carbons on top can only be up
- 3 carbons on bottom can only be down
68
racemic mixture
50/50 enantiomers
rotation=0 b/c cancel each other out
69
enantiomerically pure
1 enantiomer - either 100% og or 100% mirror
70
enantiomeric excess
one enantiomer in excess
=(observed a/pure a)x100
71
diastereomers
at least 1, but not all dashed/solid wedged flipped
72
meso compound
molecules w/ even # of chiral centers and have a plane of symmetry
73
E or Z for alkenes
Z - top priority groups are on the same side of alkene
E - top priority groups are on different sides of alkene
74
does OH or NH2 have higher priority, why
OH because O has higher priority than N
b/c we only look at atom connected to chircal center, if they are the same then you can keep going out
75
what to also check for when deciding between consituttional isomer, enantiomer, idential, diasteromer
enantiomer can be flipped over a horizontal line rather than vertical
76
if a molecule is mirror and then dashes and wedges are flipped...
identical
