Abstract
pK1 and pK2 values at zero ionic strength of some dicarboxylic acids (succinic, tartaric, malonic, malic and maleic) in 20% (w/w) acetonitrile-water at temperatures ranging from 30 °C to 60 °C have been determined using a precise EMF method. The thermodynamic parameters ΔH°, ΔG° and ΔS° of the first and the second dissociation reactions are calculated from well known equations and discussed in terms of solute-solvent interactions. An extrathermodynamic analysis of the obtained results has been performed and indicates that these dissociation reactions are entropy-controlled reactions where solute-solvent interaction plays an important role.
References
1.
Mardn
F.
,
Celadon
D.
,
Serverin
M.G.
, and
Vianello
E.
, J. Am. Chem. Soc. , 1991 , 113 , 9320 .
2.
El-Bardan
A.A.
,
El-Mallah
N.M.
, and
Hamed
E.A.
, J. Phys. Org. Chem. , 1992 , 5 , 239 .
3.
Azab
A.H.
,
Hassan
A.
, and
Khafagy
ZA.
, J. Chem. Eng. Data , 1993 , 38 , 231 .
4.
Cladera
A.
,
Tomas
C.
,
Estela
J.M.
, and
Cedra
V.
, Anal. Chim. Acta. , 1994 , 286 , 253 .
5.
Jackson
G.E.
, and
Seymour
L.F.
, Talanta , 1995 , 42 , 5 .
6.
Boraei
A.A.
,
Ahmed
I.T.
, and
Hamed
M.M.
, J. Chem. Eng. Data , 1996 , 41 , 787 .
7.
Trull
F.R.
,
Bioadjiev
S.
, and
Mc Donagh
A.F.
, J. Lipid Res. , 1997 , 38 , 1178 .
8.
Gonzalez
A.G.
,
Rosales
D.
,
Gomez Ariza
J.L.
, and
Sanz
J.F.
, Anal. Chim. Acta , 1990 , 228 , 301 .
9.
Chmurzynski
L.
,
Wawrzynow
A.
, and
Pawlak
Z.
, Electrochim. Acta , 1990 , 35 , 665 .
10.
Chmurzynski
L.
,
Liwo
A.
, and
Barczynski
P.
, Anal. Chim. Acta , 1996 , 335 , 147 .
11.
Gonzalez
A.G.
,
Herrador
M.A.
, and
Asuero
A.G.
, Anal. Chim. Acta , 1991 , 246 , 429 .
12.
Guo
Z.
,
Miyoshi
H.
,
Nagatani
K.
,
Komyoji
T.
,
Haga
T.
, and
Fujita
T.
, J. Org. Chem. , 1991 , 56 , 3692 .
13.
Monk
C.B.
, and
Amira
M.F.
, J. Chem. Soc. Faraday Trans.1 , 1978 , 74 , 1170 .
14.
Monk
C.B.
, and
Amira
M.F.
, J. Chem. Soc. Faraday Trans.1 , 1980 , 76 , 1773 .
15.
Amira
M.F.
,
El-Shazly
Sh.
, and
Khalil
M.M.
, Thermochem. Acta. , 1987 , 115 , 1 .
16.
Younes
G.
,
El-Subruiti
G.
,
Hamdan
K.
, and
Amira
M.
Proc. Int. Conf. on RTST , Lebanese American University , Beirut, Lebanon , 4-6 March 2002 , 115 .
17.
Zaghloul
A.A.
,
El Naggar
G.A.
,
El Shazly
Sh. A.
, and
Amira
M.F.
, Talanta , 1997 , 45 , 189 .
18.
Barbosa
J.
,
Beltran
J.L.
, and
Sanz-Nebot
V.
, Anal. Chim. Acta , 1994 , 288 , 271 .
19.
Zaghloul
A.A.
, Afinidad , 1996 , 462 , 123 .
20.
Zaghloul
A.A.
,
El Naggar
G.A.
, and
Amira
M.F.
, Gazz. Ital , 1996 , 126 , 735 .
21.
El Naggar
G.A.
,
Selim
S.M.
,
Zaghloul
A.A.
, and
Amira
M.F.
, Z. Phys. Chem. , 2002 , 216 , 1239 .
22.
Barbosa
J.
, and
Sanz-Nebot
V.
, Talanta , 1989 , 36 , 837 .
23.
Jahanbakhsh
G.
,
Shahin
A.
,
Mikael
K.
, and
Amin
F.
, J. Chem. Eng. Data , 2003 , 48 , 1178 .
24.
Born
M.
, Z. Phys. Chem. , 1920 , 45 , 1 .
25.
Leffler
J. E.
, and
Grunwald
E.
, Rates and equilibria of organic reactions , John Wiley and Sons , New York , 1963 . p. 155 .