Question

Calculate the osmotic pressure at 25°C across a semipermeable membrane separating seawater (1.14 M total particles) from a 0.503 M solution of aqueous NaCl.

Answer 1

The osmotic pressure can be calculated using the equation II = MRT. In this case, the osmotic pressure across a semipermeable membrane separating seawater from a NaCl solution is found to be 34 atm.

Step-by-step explanation:

The osmotic pressure can be calculated using the equation II = MRT, where I is the osmotic pressure, M is the total concentration of dissolved particles, R is the ideal gas constant, and T is the temperature.

In this case, the total concentration of dissolved particles in the solution is 1.4 M, obtained by multiplying the concentration of NaCl (0.70 M) by factor 2 (since 1 mol of NaCl produces 2 mol of particles).

Using the ideal gas constant (R = 0.0821 (L·atm)/(K · mol)) and the temperature (T = 298 K), the osmotic pressure is calculated to be 34 atm.

Answer 2

The osmotic pressure is 24.6 atm

Step-by-step explanation:

π = M . R . T . i → Formula for osmotic pressure

i = 2 ⇒ NaCl → Na⁺ + Cl⁻

i means Van't Hoff factor, which indicates the numbers of ions dissolved, by the stoichiometry.

R → Universal gases constant

T→ T° in K → T°C + 273 → 25°C + 273 = 298K

π = Osmotic pressure

Let's replace data given ⇒ π = 0.503 mol/L . 0.082L.atm/mol.K . 298K .2

π = 24.6 atm