Answer : The final concentration of the seawater is, 2.909 mole/L
Explanation :
Formula used for osmotic pressure :

where,
= osmotic pressure = 70.0 bar = 70 atm
R = solution constant = 0.0821 Latm/moleK
T= temperature of solution =

C = final concentration of seawater = ?
Now put all the given values in the above formula, we get the concentration of seawater.


Therefore, the final concentration of the seawater is, 2.909 mole/L