Question

Calculate the external pressure that must be applied to seawater, 1.12 M total ion concentration at 10 degrees celsius if the maximum concentration allowed in the product water is 171 mg/L. Assume that all the dissolved salts in the product water is sodium chloride.

Answer 1

The formula to use for this problem is
P = iCRT
where P is the external pressure
i is the van't Hoff factor
C is the concentration in mole/L
R is the gas constant
T is the temperature

Substituting with i = 2 for sodium chloride
P = 2 (171/ (1000*58) (8.314) (10 +273)
Solve for P to get the pressure in Pascals