Seawater contains 32.8 g of salts for every liter of solution. Assuming that the solute consists entirely of NaCl (in fact, over 90% of the salt is indeed NaCl), calculate the osmotic pressure of seawater at 20 âC. Express the osmotic pressure in atmospheres to three significant figures.

Question

Chemistry

Drake Hooper

16 October, 10:19

Seawater contains 32.8 g of salts for every liter of solution. Assuming that the solute consists entirely of NaCl (in fact, over 90% of the salt is indeed NaCl), calculate the osmotic pressure of seawater at 20 âC. Express the osmotic pressure in atmospheres to three significant figures.

+2

Answers (1)

Know the Answer?

Edward Briggs · Answer 1

Osmotic pressure is π = 27.6 atm

Explanation:

32.8 g of salts for every liter of solution can we understood as Molarity, but have to convert, the mass to moles (mass / molar mass)

32.8 g NaCl / 58.45 g/m = 0.561 moles

These are the moles of solute in 1L of solution.

Let's calculate the osmotic pressure by the formula

π = M. R. T. i

M, means molarity

R means Universal gases constant → 0.082 L. atm / mol. K

T means absolute temperature (K) → 20°C + 273 = 293K

i = Van't Hoff factor, for NaCl i = 2

NaCl → Na⁺ + Cl⁻

π = 0.561 mol/L. 0.082 L. atm / mol. K. 293K. 2

π = 27.6 atm