chemical thermodynamics of neptunium and plutonium - U.S. ...

2.1 Symbols, terminology and nomenclature 11Table 2.1: (continued),B )Symbols and terminologyactivity coefficient, molality basis: a B /m Bγ Bactivity coefficient, concentration basis: a B /c By Bmean ionic activity (e) , a (ν ++ν − )± = a B = a ν ++ a ν −− a ±mean ionic activity coefficient (e) , γ (ν ++ν − )± = γ ν ++ γ ν −− γ ±osmotic coefficient, molality basisφionic strength: I m = 1 ∑2 i m i zi 2 or I c = 1 ∑2 i c i zi2 ISIT ion interaction coefficient between substance B 1 and ε (B1substance B 22stoichiometric coefficient of substance B (negative for ν Breactants, positive for products)general equation for a chemical reaction0 = ∑ B ν BBequilibrium constant (f)Krate constantkFaraday constantFcharge number of an ion B (positive for cations, negative for z Banions)charge number of a cell reactionnelectromotive forceEpH =−log 10 [a H +/(mol · kg −1 )]electrolytic conductivityκsuperscript for standard state (g)◦(a) The ratio of the average mass per formula unit of a substance to12 1 of the mass of an atomof nuclide 12 C.(b) cf. Sections 1.2 and 3.6 of the IUPAC manual [79WHI].(c) This quantity is called “amount-of-substance concentration” in the IUPAC manual [79WHI].A solution with a concentration equal to 0.1mol· dm −3 is called a 0.1 molar solution or a0.1 M solution.(d) A solution having a molality equal to 0.1mol· kg −1 is called a 0.1 molal solution or a 0.1 msolution.(e) For an electrolyte N ν+ X ν− which dissociates into ν ± (= ν + + ν − ) ions, in an aqueoussolution with concentration m, the individual cationic molality and activity coefficient arem + (= ν + m) and γ + (= a + /m + ). A similar definition is used for the anionic symbols.Electrical neutrality requires that ν + z + = ν − z − .(f) Special notations for equilibrium constants are outlined in Section 2.1.6. In some cases, K cis used to indicate a concentration constant in molar units, and K m a constant in molal units.(g) See Section 2.3.1.