Question

In reverse osmosis, water flows out of a salt solution until the osmotic pressure of the solution equals the applied pressure. If a pressure of 70.0 bar is applied to seawater, what will be the final concentration of the seawater at 20 ∘C when reverse osmosis stops?

Answer 1

Answer : The final concentration of the seawater is, 2.909 mole/L

Explanation :

Formula used for osmotic pressure :

$\pi=CRT$

where,

$\pi$ = osmotic pressure  = 70.0 bar = 70 atm

R = solution constant  = 0.0821 Latm/moleK

T= temperature of solution = $20^oC=273+20=293K$

C = final concentration of seawater = ?

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

$70atm=C\times 0.0821Latm/moleK\times 293K$

$C=2.909mole/L$

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