S °/oo = 0.8996 25 27297.20 Ris Pe 280852 cc 
$4 5798674 Bo = We 301d tee 
15 
(5) 
where R, is the ratio of conductivity of sample water to 
that of “standard water having a salinity of exactly 35 °%/oo, 
both samples being at the same temperature, t°C, and under 
a pressure Of leatmosphere: 
= 10.67869 Ris 
If measurements are made at a temperature other than 
i5S°C,. but. not very tar from 15°C, Ris may be computed by 
2 
_ =5 : 
Rig = Rp + 10 RR “yes (96.7 - 72.0R, + 372 5Ry, 
- (0.63 + 0.21R,°) (t-15)] (6) 
Bissett Berman provides standard tables for direct eval- 
uation of salinity from conductivity ratio and also for 
temperature corrections. 
Theory 
In developing a comprehensive theory for thermodynamic 
properties of sea water, two important questions arise. 
First, can sea water be treated as a two-component system? 
Our present knowledge and understanding of multicomponent 
electrolyte solutions is so limited that we are left with 
little choice but to consider sea salts as a Single -com- 
ponent. Fortunately, the relative proportions of major 
constituents of sea salts remain nearly constant (7) so 
that, to a first approximation, the ocean's salts may 
indeed be considered to be of a constant composition. 
Table 7 gives the composition of sea salts, based on 
Sverdrup's (8) composition of sea water. This permits us 
to treat sea salts as a single component with an apparent 
molecular weight of 62.83 (9). 
The properties, of sea water. depend upon the concentra; 
tion and the relative amounts of ions present. If we regard 
sea water as a binary mixture of sea salts and water, the 
enthalpy of the solution, H, is given by 
H = xoLe = xLg + (1-x)Ly (7) 
30 
