Download Henry`s Law Henry`s Law continued Example: dissolved CO2

Henry’s Law
equilibrium
vapor
Henry’s Law continued
of a gas in solution with its
Pgas = kX dissolved _ gas
K
orange dot (g) ' orange dot (sol’n)
k (atm × 10-3)
0 °C 25 °C 37 °C
He
133 141 140
N2
51
85
99
O2
26
43
51
CH4
23
39
46
CO2 0.72 1.61 2.16
... -
⌧ 2
Example: dissolved CO2
... -
⌧ 3
Osmotic pressure
What is the amount of CO2 dissolved in the oceans?
Atmospheric PCO2 = 3.85 × 10-4 atm, Vocean = 1.37 ×
1015 m3 and kCO2 = 2 × 103 atm.
atm
... -
⌧ 4
... -
⌧ 5
Example: osmotic pressure of a 100 mM solution
What is the osmotic pressure of a 100 mM sucrose
solution at T = 25 °C?
... -
⌧ 6
Example: osmotic pressure of a 100 mM solution
... -
Molecular weight determination
What is the osmotic pressure of a 100 mM NaCl solution
at T = 25 °C?
... -
⌧ 7
⌧ 8
Π = cRT
... -
⌧ 9
Example: using osmotic pressure
Phase partitioning
A 0.1 g/L solution of creatine is placed in an osmometer
against pure water at 25 °C. The osmotic pressure is
measured at 0.0187
0 0187 atm.
atm What is the MW of creatine?
... -
⌧ 10
μ°(hepta
ane) - μ°(aq) (kJ/m
mol)
-50
Standard Gibbs
free energy of
transfer from
water to heptane
O
n
O
... -
⌧ 11
Example: Gibbs free energy of transfer
Aliphatic carboxylic acids
-60
60
Two different solvents, each
making a fully saturated
solution with the same solid.
The concentration of creatine in blood is 20 mg/mL and
in urine is 750 mg/mL. What is the Gibbs free energy of
transfer per mole from blood to urine at 37 °C?
C?
-40
-30
-20
-10
8
12
16
20
No. of carbon atoms
... -
24
⌧ 12
... -
⌧ 13
Example: amino acid solubility
Example: amino acid solubility
The solubilities of glycine and valine in water and
ethanol at 25 °C are given below. What is the standard
state Gibbs free energy of transfer per mole of glycine
f
from
solid
lid to
t aqueous solution?
l ti ?
Gly: 3.09 M in water, 4.04 × 10-4 M in EtOH
Val: 0.60 M in water, 1.32 × 10-4 M in EtOH
... -
⌧ 14
Example: amino acid solubility
Gly: 3.09 M in water, 4.04 × 10-4 M in EtOH
Val: 0.60 M in water, 1.32 × 10-4 M in EtOH
⌧ Gly: 3.09 M in water, 4.04 × 10-44 M in EtOH
Val: 0.60 M in water, 1.32 × 10-4 M in EtOH
... -
⌧ 15
Example: protein stability upon G → V mutation
What is the standard state Gibbs free energy of transfer
per mole of the Val side chain from ethanol to aqueous
solution at 25 °C?
... -
What is the standard state Gibbs free energy of transfer
per mole of glycine from ethanol to aqueous solution?
Suppose a glycine residue in the hydrophobic interior of
a protein is mutated to a valine. Will this mutation make
the protein more stable at 25 °C?
C?
Gly: 3.09 M in water, 4.04 × 10-4 M in EtOH
Val: 0.60 M in water, 1.32 × 10-4 M in EtOH
16
... -
⌧ 17
Boiling point increase continued
P
∗
Psolvent
= solvent
X solvent
Boiling point increase
Show that the BP of a
solvent increases as
solute
l t concentration
t ti
increases.
Let the pure solvent boiling T be called T0
and the solution boiling T be called Tboil
Start from Raoult’s law:
Apply the Clausius-Clapyron equation:
∗
Psolvent = X solvent Psolvent
ln
... -
⌧ 18
P2,vap
P1,vap
... -
=−
0
ΔH vap
⎛1 1⎞
⎜ − ⎟
R ⎜⎝ T2 T1 ⎟⎠
⌧ 19