Chapter 2 Flashcards
As size of atom increases, acidity ______
increases
a Low pKa value indicates ____ acidity, while a low Ka value indicates _____ acidity
high
low
Inductive effects
An inductive effect is the pull of electron density through delta bondas caused by electronegativity differences in atoms.
The more an atom is stabilized, more ____ it is.
stabilized
Which is more acidic?
CH3CH2O-H
CF3CH2O-H
Which effect is responsible for this?
CF3CH2O-H
because the F3 stabilizes the molecule.
In the first molecule, all the electron density is stuck in O
electron withdrawing inductive effect
The more electronegative the atom and the closer it is to the site of the negative charge, the (greater/lesser) the stabilizing effect which leads to (greater/lesser) acidity
greater
greater
Resonance Effects (increase/decrease) acidity
increase
Why is acetic acid stronger than ethanal acid
Because acetic acid has resonance on the COOH
Resonance delocalization makes CH3COO- (more/less) stables
more
High s character % =
higher stability and acidity
Which is the strongest acid?
A: CH3CH3
B: CH2=CH2
C: H-C=-C-H
C. Because of the triple bond. It increases S-character
Rank these hybridization types in order of increasing acidity
sp2, sp3, sp
sp3
Elemental trend on acidity:
Acidity increases as move to the right and to the bottom of the periodic table.
Inductive effects on acidity
The acidity of H-A increases with the presence of election-withdrawing groups in A
Resonance effects on acidity:
The Acidity of H-A increases when the conjugate base A- is resonance stabilized
Acid base reactions always favor the formation of the (weaker/stronger) acid and base pair
weaker
So if you have a stronger acid and stronger base, the reaction arrow will favor the (strong/weak side)
weak
Strong bases of (strong/weak) pKa values usually >__ pKa
weak
12
Carbanions are weak/strong bases
strong
A lewis acid is an electron pair _____
accepter
A lewis base is an electron pair ____
donor
Lewis bases and Bronsted-lowry bases both _____ an electron pair or an electron pair in a __ bond
donate
pie
A lewis acid-base reaction is one in which:
One species donates an electron pair to another
A lewis acid-base association reaction is one in which:
one bond is formed and no bonds are broken
A lewis acid is synonymous with (nucleophile/electrophile)
electrophile
A lewis base is also called a (nucleophile/electrophile)
nucleophile
A lewis acid-base displacement reaction is one in which:
it mimics a double displacement style.
Steps in acid displacement reactions:
1: Identify the lewis acid and base,
2. Draw curved arrow from the electron pair of the base to the electron-deficient atom of the acid.
3. Count electron pairs and break a bond when needed to keep the correct number of valence electrons
