The document discusses various chemical equations and thermodynamic properties related to solute interactions, ligand binding, and the significance of free energy changes (ΔG°) and entropy changes (ΔS°). It includes specific reactions involving lead ions (Pb2+) and acetate ions (CH3COO−), detailing their equilibrium constants and pKa values in different solvents. Additionally, it mentions the positive value of ΔS° in the context of enzyme interactions, indicating an increase in disorder during these processes.

1. Department
of
Chemistry
PbI2(s)  Pb(aq)
2+
+ 2I(aq)
−
K = [Pb2+
][I−
]2
ΔGo
= 46.1 kJ/mol ⇒ [Pb2+
] = 1.14 ×10−3
M
measured: [Pb2+
] = 1.37 ×10−3
M
K = e−ΔGo
/RT
Explain
the
difference

2. Department
of
Chemistry
solute(water)  solute(octanol)
log(Pwo)
=
3.37
ΔGo
= −19.2 kJ/mol
What
is
the
most
probable
sign
of
ΔSo
and
why?

3. Department
of
Chemistry
CH3COOH  CH3COO−
+ H+
pKa = −log Ka( )
Ka =
[CH3COO−
][H+
]
[CH3COOH]
the
pKa
in
water
is
4.76.
Is
the
pKa
higher
or
lower
DMSO
and
why?
S
ε
=
47

4. Department
of
Chemistry
P + L  P ⋅L
Ligand
binding
to
the
enzyme
carbonic
anhydrase
(at
25
oC)
ΔSo
9.7
67.4
J/molK
DOI:
10.1002/anie.201301813
Explain
the
difference
in
ΔSo

5. Department
of
Chemistry
Explain
why
ΔSo
is
posiUve
hWp://youtu.be/zKNmBjqGijI
ΔSo
= 25.8 J/molK
at 25 o
C
(Video
of
benzamidine
binding
to
trypsin)