SECT. 1] 



PHYSICAL PROPERTIES OF SEA-WATER 



27 



assuming that the thermal diifusivity , kIpCp, of sea-water is equal to that of pure 

 water. The diffusivity D is usually estimated by assuming it to be equal to the 

 diifusivity of sodium chloride in a solution of similar concentration to that of 

 sea-water. 



Table V 



Transport Phenomena in Water at a Pressure of 1 atm 

 (Montgomery, 1957) 



Name, symbol, units 



Pure Water 



O^C 



20°C 



Sea-Water, 

 (salinity 35 per mille) 



0°C 



20°C 



Dynamic viscosity, 



r), g cm~l sec~l = poise 

 Thermal conductivity, 



k, watt cm-1 °C-l 

 Kinematic viscosity, 



v — T^lp, cm2 sec~l 

 Thermal diffusivity,*^ 



K = K/cpp, cm2 sec~i 

 Diffusivity, D, cm^ sec~l : 



NaCl 



N2 



O2 

 Prandtl number, Np = v/k 



0.01787« 0.01002^' 



0.00566C 0.00599c 



0.01787 0.01004 



0.00134 0.00143 



0.0000074« 0.0000141/ 



O.OOOOlOes' 0.0000169? 



0.000021'^ 



13.3 7.0 



0.01877« 0.01075a 



0.00563^ 0.00596C 



0.01826 0.01049 



0.00139 0.00149 



0.0000068« 0.0000129/ 



13.1 



7.0 



a Yasuo Miyake and Masami Koizumi. The Measurement of the Viscosity Coefficient of 

 Sea-Water. J. Mar. Res., 7, 63-66 (1948). Values taken from their Table I and reduced 

 by 0.00007 poise to agree with Swindells et al. (Table III presents smoothed values for 0, 

 1, . . ., 30°C, chlorinity 0, 1, . . ., 20 per mille.) 



b J. F. Swindells, J. R. Coe, Jr., and T. B. Godfrey. Absolute Viscosity of Water at 20°C. 

 J. Res. Nat. Bur. Standards, 48, 1-31 (1952). 



<^ L. Riedel. Die Warmeleitfahigkeit von wassrigen Losungen starker Elektrolyte. 

 Chem.-Inst.-Technik, 33, 59-64 (1951). 



'^ Thermal diffusivity is also called thermometric conductivity. 



« Values for 0°C calculated from those at 20°C by use of temperature coefficient of L. W. 

 Oholm. tJber die Hydrodiffusion der Elektrolyte. Z. physik. Chem., 50, 309-349 (1904). 



/ A. R. Gordon. The Diffusion Constant of an Electrolyte, and Its Relation to Concentra- 

 tion. J. Chem. Phys., 5, 522-526 (1937). Gordon used measurements by B. W. Clack. On 

 the Study of Diffusion in Liquids by an Optical Method. Proc. Phys. Soc. London, 36, 

 313-335 (1924). R. H. Stokes. The Diffusion Coefficients of Eight Uni-univalent Electro- 

 lytes in Aqueous Solution at 25°C. J. Amer. Chem. Soc, 72, 2243-2247 (1950). 



? Gustav Tammann and Vitus Jessen. Uber die Diffusionskoeffizienten von Gasen in 

 Wasser und ihre Temperaturabhangigkeit. Z. anorg. Chem., 179, 125-144 (1929). 



* Tor Carlson. The Diffusion of Oxygen in Water. J. Amer. Chem. Soc, 33, 1027-1032 

 (1911) ; I. M. Kolthoff and C. S. Miller. The Reduction of Oxygen at the Dropping Mercury 

 Electrode. J. Amer. Chem. Soc, 63, 1013-1017 (1941) ; H. A. Laitenen and I. M. Kolthoff. 

 Voltammetry with Stationary Microelectrodes of Platinum Wire. J. Phys. Chem., 45, 

 1061-1079 (1941). 



