Question

The osmotic pressure of a solution formed by dissolving 75.0 mg of aspirin (c9h8o4) in 0.250 l of water at 25 °c is ________ atm.

Answer 1

Answer is: the osmotic pressure of aqueous solution of aspirin is 0.0407 atm.

m(C₉H₈O₄) = 75 mg ÷ 1000 mg/g = 0.075 g.

n(C₉H₈O₄) = 0.075 g ÷ 180.16 g/mol.

n(C₉H₈O₄) = 0.000416 mol.

c(C₉H₈O₄) = 0.000416 mol ÷ 0.250 L.

c(C₉H₈O₄) = 0.00167 M; concentration of solution.

T(C₉H₈O₄) = 25°C = 298.15 K; temperature in Kelvins.

R = 0.08206 L•atm/mol•K; universal gas constant.

π = c(C₉H₈O₄) • T(C₉H₈O₄) • R.

π = 0.00167 mol/L • 298.15 K • 0.08206 L•atm/mol•K.

π = 0.0407 atm.