Topic 4: Acid & Bases pt 4

Question 1

(6) Solvatation Affectes Acidity

Answer 1

Solvation: Stabilization of ions by solvent

6.Stabilization of ions by solvents (solvation)

Solvation provides stabilization

Question 2

(6) Solvatation Affectes Acidity pt 1

Answer 2

Comparison of alcohol acidities

ethanol(CH3), propan-2-ol (OH-CH3CH3), and 2-methylpropan-2-ol

Crowding inhibiting solvation (Increase from left to right)

Solvation, stability of anion, acidity
(Stabilization right to left)

Question 3

Factors Affect Acidity (6 factors)

Answer 3

1. Electronegativity
   2.Atomic size
2. Resonance stabilization
3. Substituents (Inductive effect)
4. Hybridization (More s means more stable)
5. Solvation (Less crowded molecules the CB can be stabilized by solvents or hydrogen bonding.

Question 4

Acid Strenghts

Answer 4

Very Strong Acid: pKA<1 (protonated alcohol, protonated water, and protonated carboxylic acid)

Moderately Strong Acids: pKa=1-3 HF pKa-3

Weak Acids (fruits)= pKa:3-5 (carboxylic acid) pKa=5

Very weak acids: pKa: 5-15 (protonated amine) pka-10

Extremely weak acids: pKa>15 (an alcohol and water) pKa-15

Stronger the acid, the LARGER the Ka
Stronger the acid, the smaller the pKa

Question 5

Acid-Base Equilibria

Answer 5

Which way will the reaction go?

CH3COOH + NH3 ⇄ CH3COO- + NH4 ←(weaker acid)
pKa= 4.76. (SB). (WB). pka=9.4 (WA)
The equilibrium favors the formation of the weaker acid.

CH3CH2OH + CH3NH2 ⇄ CH3CH2O-+CH3NH3
(pka=15.9) (pKa=10.7)
Weaker Acid ( SA)