Physical Chemistry of Foods
Answer The simplest solution appears to be to calculate the molar concentration, which is for Ca (molar mass 40) 2.5 and for cit ...
2.4 RECAPITULATION Thermodynamics describes the (changes in) energy (or enthalpyH)andin entropyðSÞof a system; entropy is a meas ...
BIBLIOGRAPHY For a general treatment of chemical thermodynamics and the properties of solutions, see any of the textbooks on phy ...
3 Bonds and Interaction Forces Atoms, groups of atoms, ions, molecules, macromolecules, and particles always are subject to forc ...
forceðFÞgenerally is the derivative of the energyðF¼dU=dhÞand, as illustrated in the figure, the net force is thus zero where t ...
TABLE3.1 Overview of Possible Interaction Forces Between Atoms, Molecules, and Particles Type of interaction Energy involved, ðk ...
therefore calledhard-core repulsion. If it is ions that approach each other, the interaction is often called Born repulsion. 3.1 ...
charges are of opposite sign and positive (repulsive) if of the same sign. The force is inversely proportional to the square of ...
Dipole–dipole: dipoles on average orient themselves so that the positive end of one molecule is close to the negative one of an ...
are additive, however, the decay between larger bodies may be much weaker. This is discussed in Section 12.2.1. Hydrogen Bonds. ...
3.2 SOLVATION As mentioned above, net attractive interactions occur between all pairs of molecules (excluding ions for the momen ...
added that entropic effects can be involved in the interactions if the solvent has some structure (as in water), and one then sp ...
mostly weak in this case. It appears that water molecules adjacent to an -OH group may have either a somewhat shorter or a somew ...
‘‘rule’’ that changes in enthalpy and entropy are roughly independent of temperature. Anyway, the hydrophobic effect exists by v ...
these series are approximately as follows: SO^24 >HPO 42 >acetate>citrate>Cl>NO 3 >I>SCN NHþ 4 > ...
decreases the activity coefficient of the solute and increases its solubility. In other cases, negative solvation occurs, leadin ...
4 Reaction Kinetics Chemical kinetics is generally discussed with respect to reactions between molecules (or ions or radicals) i ...
4.1 REACTION ORDER Before coming to factors determining reaction rates, it is useful to review the manner in which concentration ...
TABLE4.1 Overview of Rate Equations Order Rate equation Integrated form t 0 : 5 Units ofk 0 d½A dt ¼k ½A 0 ½A¼kt ½A 0 2 k ...
equilibrium situation. To be sure, the relaxation time has physical significance only for a first-order reaction, and many chang ...
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