Acids and Bases Flashcards Preview

Organic Chemistry I > Acids and Bases > Flashcards

Flashcards in Acids and Bases Deck (26)
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1
Q

what is a bronsted acid

A

proton H+ donor

2
Q

what is a bronsted base

A

proton H+ acceptor

3
Q

what is a lewis acid

A

e- pair acceptor

electrophile

4
Q

what is a lewis base

A

e- pair donor

nucleophile

5
Q

large Ka

A

small pKa

stronger acid, rxn goes forward

6
Q

pKa formula

A

pKa = -logKa

7
Q

when pKa = pH

A

50% of acid has dissociated

8
Q

if pH > pKa

A

molecule is in deprotonated state

9
Q

if pH < pKa

A

molecule is in protonated state

10
Q

a strong acid will have a weak…

A

conj base

11
Q

a strong base will have a weak…

A

conj acid

12
Q

weak conj bases are…

A

more stable, less reactive

reverse rxn does not occur

13
Q

to determine conj base stability consider

A

Atom (EN + size)
Resonance
Induction
Orbital Hybridization

14
Q

“Atom” stability

A

acidity of HA goes up as you go –> row

acidity of HA goes up as you go down a group

15
Q

why EN?

A

more EN can hold a (-) charge

more EN has a greater dipole

easier to remove the H+

16
Q

why size?

A

(-) charge spread over a larger area

bond strength is lower as you go down a group

17
Q

“Resonance”

A

more resonance, (-) is delocalized and more stable

18
Q

“Inductive forces”

A

presence of additional EN atoms more stable

involves sigma bonds

19
Q

“Orbital Hybridization”

A

more stable sp (50% s char.) > sp2 (33% s char.) > sp3 (25% s char.) less stable

triple bonds > double bonds > single bonds

20
Q

why orbital hybridization?

A

more s-char, e- held more closely to nucleus, more stable

21
Q

strength of Lewis acid

A

stronger = better electrophile

  1. molecules with unfilled octet
  2. molecules w/ (+) charge AND resonance
  3. molecules with partial (+) charge
22
Q

strength of Lewis base

A

stronger = better nucleophile

  1. less EN attracts e- less
  2. molecules w/ localized e-
  3. molecules w/ (-) charge
23
Q

most stable base is the

A

least basic

24
Q

least stable base is the

A

most basic

25
Q

most acidic has

A

the most stable (weakest) base

26
Q

least acidic has

A

the least stable (strongest) base