Acid-Base and pH II Flashcards
1
Q
Stength of acid
A
- Pka determines the strength of the acid not the pH.
- Lower the pH the more acidic
2
Q
pH
A
- Log10()
3
Q
Strong acid
A
- Completely ionised in water
4
Q
Strong base
A
- Kw 10^14/(OH) = pH
- Completely dissacociates
5
Q
Concentration units in Pharmacy
A
mol/L
6
Q
Weak acid
A
- Partially dissacociate is a reversible reaction
- 1/2 pka - log[HA] = pH
7
Q
Weak base
A
pH = pKw - 1/2 pKb = 1/2 log [B]
8
Q
pKa
A
pH when exactly half is dissociated
9
Q
Henderson–Hasselbalch
A
if pH > pKa [A-] is 10x bigger than [HA]
if pH < pKa [HA] is 10x bigger than [A-]
10
Q
weak acid + weak base
A
Ka cation > Kb anion: solution acidic
Kb anion > Ka cation: solution basic
Ka & Kb similar: solution is close to neutral
11
Q
Henderson-Hasselbalch titration
A
pH = pKa +log [base/acid]
12
Q
Acid base interaction in titration
A
- [OH] increase
- [H3O+] decrease
- pH increse
13
Q
Buffer
A
- Resisting the change in pH the is a cojugate base to provide the H+ or OH-
