If a 0.100 M solution of potassium sulfate has an osmotic pressure at 25.0C, what is the i value for the solution?

Answer 1

You didn't supply the osmotic pressure at 25ºC. Whatever it is, use it in the following expression to find the value of i, the van't Hoff factor. It should be close to a value of 3 since potassium sulfate = K₂SO₄ which will dissociate into 3 ions, 2K⁺ + SO₄^2-.

Osmotic pressure = π = iMRT

π = whatever value is given

i = van't Hoff factor = ?

M = molarity = 0.1 mol/L

R = gas constant = 0.0821 Latm/Kmol (assuming the osmotic pressure is in atm)

T = temperature in K = 25 + 273 = 198

Plug in the values and solve for i