Answer:
-4.92 bars
Step-by-step explanation:
The water potential of a solution is the sum of the pressure potential and the solute potential of the solution. This can be mathematically expressed as;
Фw = Фp + Фs, where Фw = water potential, Фp = pressure potential, and Фs = solute potential.
For a solution that is in an open beaker, the Фp = 0. hence
Фw = -Фs
Also,
Фs = iCRT, where i = number of particles the molecule will make in water (1 for sucrose), C = molar concentration, R = pressure constant (usually 0.0831 liter bar/mole K), and T = temperature (in kelvin).
In this case, i = 1, C = 0.20 M, R = 0.0831, T = 273+23
Фs = 1 x 0.20 x 0.0831 x 296 = 4.92 bars
Therefore,
Фw = -4.92 bars