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Flashcards in Solution Deck (17)
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1

Henderson-Hasselbach equation for acid

pH = pKa + log [A-]/[HA]
pH = pKa + log [ionised]/[unionesd]
pH = pKa + log [salt]/[acid]
pH = pKa + log [conjugate base]/[acid]

2

Henderson-Hasselbach equation for base

pH = pKa + log [B]/[BH+]
pH = pKa + log [unionised]/[ionised]
pH = pKa + log [base]/[salt]
pH = pKa + log [base]/[conjugate acid]

3

What is Co?

-Intrinsic solubility
-concentration of unionised drug
-Co = [B] or [HA}

4

What is Cs?

-Saturated solubility
-concentration of unionised and ionised drug
- Cs = [B] + {BH+] or [HA} + [A-]

5

What is Cs-Co

-concentration of ionised drug
calculation:
Cs - Co = saturated solubility - intrinsic solubility
Cs - Co = ( [B] + [BH+] ) - [B] or ( [HA] + [A-] ) - [A-]
Cs - Co = [BH+] or [A-]

6

H-H equation for acid with Cs and Co

pH = pKa + log [ionised/unionesd]
pH = pKa + log [ (Cs - Co)/Co ]

7

H-H equation for base with Cs and Co

pH = pKa + log [ Co/(Cs - Co) ]
pH = pKa + log [unionised/ionised]

8

Protogenic Solvent

-Donates protons
ie CH3COOH
-Bronsted acid

9

Protophilic solvent

-Accept protons
*key=philic
ie NH3
-Bronsted base

10

Aprotic solvent

Neither accepts nor donates protons
ie DMSO

11

Amphiprotic

Can both accept or donates protons
ie H2O, alcohols
*key= amphi

12

important Kw equation

pKw=14
pKw=pH + pOH
pKw=pKa + pKb

13

Measures of concentration

-Molarity
-Mole fraction
-Molality

14

Molarity

Moles per litre

15

Mole fraction

Mole fraction of a species in a mixture(Xa)
-Xa = n(a)/n
Xa = no. of mole of compound A/total number of moles

16

Molality

Mx=no of solute/ mass of solvent
Mx=moles/kg = Molality

17

Nucleation

-occurs at the molecular level
-molecules in solution join together to form a cluster
-when it reaches a certain critical size, it will become stable and will grow into crystal