abOUterom ce 
The bicarbonate ions are removed by adding concentrated 
sulfuric acid to the original sea water, to reduce, the, pH ‘to 
about 4.5 (about 3.2 ml of conc. sulfurzG acid, (specific 
gravity 1.84, are required for 45 liters jof sea) water). a14 
batch of about 40 liters is prepared for each concentration 
and kept in a 50-liter polyethylene bottle. The solution 
for a run is drawn from these bottles. Each run required 
about +135 liters of solution: 
Concentrates of sea water are prepared by boiling the 
acidified sea water at atmospheric pressure to the required 
concentration and stored. It was found that the pH of the 
acidified solution did not change appreciably during 
CONGCENt ration. 
The procedure described below is used for runs of 
distilled water as well as the sea water solutions. (No 
samples are taken in the case of distilled water.) A run 
of distilled water is made once after two runs of sea water. 
This is necessary to check the calibration at each pressure. 
Start up - The condenser water is first turned on. 
Then the solution (or distilled water) is sucked into the 
ebulliometer, through the charge-discharge tube, to a 
height of 25". The main heaters are then switched on and 
the solution allowed to boil. In about one hour, vapor 
rises to the condenser and starts to condense. Tape 
heaters around the aluminum cylinder and the vapor tube are 
switched on. Valves on the condensate lines are kept open. 
About 20 minutes later, the first drops of condensate start 
coming down through the ports indicating that the condensate 
reservoirs are full. Now the heaters in these reservoirs 
are switched on. 
Recording temperatures - The pressure is brought 
to the desired value by putting the pressure controller on 
control mode (with vacuum pump on and nitrogen line 
pressure So 0psig);, and, changine the set point to %the 
desired value. About 20 minutes are required for equili- 
bration. During this time the condensate temperature is 
monitored to ensure equilibrium. 
When the condensate temperature is steady, the cali- 
bration of the temperature probes for the particular 
pressure 1S Started. Temperatures Tl, 02, and 'Ti-?lZ are 
46 
