THE VISCOSITY OF SEA WATER 



On the basis of what now appears to have been a superficial similarity 

 of their activation energies electrical conductivity, viscous flow, self- 

 diffusion, and dielectric relaxation in water were believed to all involve 

 the same rate-determining step (Glass tone, Laidler and Eyring, 1941, and 

 Wang, Robinson and Edelman, 1953). However, more detailed examination, 

 especially in the to +10°C region reveals important differences. Miller 

 (1963) reports no discontinuoties in E^ vis. ^^ ^°^ ^^ the viscosity of 

 water and our recent measurements (Home, Courant, Johnson, and Margosian, 

 1964) on both pure water and sea water yield the same result. E . , unlike 



y \ a .VIS . ' 



Ea cond. shows no maximum (Fig 5) hence the mechanism of viscous flow is 

 different from that of normal conduction, possibly involving some kind of 

 rotational tumbling of the clusters through the free water. 



At the present time we are just completing an experimental study of the 

 effect of pressure on the viscosity of pure water and sea water. The data 

 have not been analyzed yet in detail, but qualitatively they show the same 

 phemenona revealed by the much earlier work of Cohen (1892) on aqueous NaCl 

 solutions, namely an initial decrease in viscosity with increasing pressure 

 due to the destruction of the structure in liquid water and then, after the 

 border has been destroyed, an increase in viscosity with increasing pressure 

 as observed for "normal" non-associated liquids. 



THE ELECTRICAL CONDUCTIVITY OF AQUEOUS MAGNESIUM SULFATE SOLUTIONS 



Earlier we mentioned that MgSO, is a very powerful structure maker. 

 Ea cond. °^ aqueous MgSO^ solutions (Home and Johnson, 1965) has a tempera- 

 ture dependence similar to that of viscous flow rather than normal ionic 

 conduction (Fig 5). Evidently MgSO^ is so highly hydrated that its species 

 are too large to fit into the "holes" and as a consequence the mechanism of 

 their transport in aqueous solution resembles that of the water clusters. 



MISCELLANEOUS STUDIES 



In addition to fundamental research on the physical-chemistry of sea water 

 we have also turned our attention to problems of more immediate practical con- 

 sequence. Our interest in marine corrosion at great depths prompted us to 

 examine the effect of pressure on the dissociation constant of the chloride 

 complex of a constructional metal. 



^^^ F^cr^ ~ ""^^ 



€/ 



Due to electros triction (see above) the application of pressure tends to 

 force this reaction to the right increasing the dissociation constant by 

 about 20 fold in going from 1 to 2,000 atmospheres (Home, Myers and Fry- 

 singer, 1964). The performance of unshielded electro-chemical devices such 

 as batteries on the ocean floor has been of concern to us (Home, 1963) and 



230 



