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Chapter VII Reactivity at Dislocation….
The standard change in the internal energy in passing from the initial to the
activated state (∆ # U o ) can be represented as,
E = RT + ∆ # U o (7.20)
Enthalpy is a state function whose absolute value cannot be known easily; it
(∆ # H o ) can be ascertained, either by direct method or indirectly. An increase in
the enthalpy of a system, for which ∆ # H o is positive, is referred to as an
endothermic process. Conversely, loss of heat from a system, for which ∆ # H o has
negative value, is referred to as an exothermic process.
Sample
Table: 7.2 Thermodynamics parameters for pure and amino acids doped KDP crystals.
Standard
Entropy Δ # S
JKMol -1
Standard
Enthalpy Δ # H
kJ Mol -1
273
Standard Gibbs
free energy ∆ # G o
kJ Mol -1
Standard change
in internal energy
Δ # U kJ Mol -1
Pure KDP -45.9311 16.920 30.837 19.434
KDP+0.3 Wt.%
L-histidine
KDP+0.4 Wt.%
L-histidine
KDP+0.5 Wt.%
L-histidine
KDP+0.3 Wt.%
L-threonine
KDP+0.4 Wt.%
L-threonine
KDP+0.5 Wt.%
L-threonine
KDP+0.3 Wt.%
DL-methionine
KDP+0.4 Wt.%
DL-methionine
KDP+0.5 Wt.%
DL-methionine
-53.2603 14.560 30.698 17.074
-50.6894 15.300 30.659 17.814
-52.4012 14.790 30.667 17.304
-56.9187 13.598 30.844 16.112
-57.7279 13.400 30.891 15.914
-57.3492 13.480 30.857 15.994
-63.7978 12.110 31.440 14.624
-63.4041 12.180 31.391 14.694
-62.1054 12.440 31.258 14.954