Standard Ethalpies and Free energies of Formation, and Standard Third-Law Entropies, at 298oK
 
This table gives the standard heat (DHo) and free energies (DGo) of formation of compounds from elements in their standard states and the thermodynamic, or third-law entropies (So) of compounds, all at 298oK. The state of the compound is specified by: (g) = gas; (l) = liquid; (s) = solid; (aq) = aqueous solution.

Substance

DHo298
(kcal mole-1)

DGo298
(kcal mole-1)

So298
(cal deg-1mole-1)
H2 (g) 0.0 0.0 31.211
I2 (g) 14.876 4.63 62.280
I2 (s) 0.0 0.0 27.9
I2 (aq) 5.0 3.926 -
N2 (g) 0.0 0.0 45.767
O2 (g) 0.0 0.0 49.003
H2O(g) -57.798 -54.635 45.106
H2O (l) -68.317 -56.690 16.716
NO(g) 21.600 20.719 50.339
HNO3 (l) -41.40 -19.10 37.19
HNO3 (aq) -49.37 -26.41 35.0

PHYSICAL CONSTANTS  
Avogadro's number

N = 6.022169 x 1023 mole-1
(12C = exactly 12)
Gas constant

R = 1.98726 cal deg-1 mole-1
R = 8.314 JK-1 mol-1

INTERNATIONAL SYSTEM OF UNITS (SI)

In 1960, the International Bureau of Weights and Measures established the International System of Units (SI) to simplify communication among world scientists. In this text the authors have not been rigorous about using only SI units, because at the time of publication the traditional units (e.g., angstroms and calories) were still common. The present trend among scientists is toward the use of strict SI units.
The International System has seven base units: metre (m), kilogram (kg), second (s), ampere (A), kelvin (K), mole (mol), and candela (cd). Supplementary units are radian (rad) for plane angle and steradian (sr) for solid angle. All other SI units are derived from these base and supplementary units. The following table lists examples relevant to "The Rates of Chemical Reactions"

Physical Quantity

SI unit
(sysmbol)

Conversion factors
Energy joule (J = N m) 1 cal (thermochemical) = 4.184 J (exactly)
Thermodynamic Temperature kelvin (K)

replaces oK; Celsius temperature (t) = T - 273.15 K in oC
Amount of substance mole (mol)  
Concentration mole per cubic metre (mol m-3) 1 mole liter-1 = 103 mol m-3 (exactly)