Question

The value for water potential in root tissue was found to be -4.5 bars. If the root tissue is placed in a 0.3 M solution of sucrose at 20°C in an open beaker, what is the 4 of the solution, AND in which direction would the net flow of water be?

Answer 1

The water potential of the 0.3 M sucrose solution at 20°C in an open beaker is -7.38 bars.

The net flow of water would be from the solution into the root tissue.

Step-by-step explanation:

In this scenario, the water potential of the root tissue is -4.5 bars and it is placed in a 0.3 M solution of sucrose at 20°C in an open beaker.

To determine the water potential of the solution, we need to consider the solute potential (Ys) of sucrose and the pressure potential (Yp) of the solution.

The solute potential (Ys) can be calculated using the van 't Hoff equation:

Ys = -MiRT, ( where M is the molar concentration of the solute, i is the van 't Hoff factor, R is the ideal gas constant, and T is the temperature in Kelvin degrees ).

By substituting the given values, we can calculate the solute potential (Ys):

Ys = -(0.3)(1)(0.0821)(293)

= -7.38 bars

Next, we need to calculate the pressure potential (Yp) of the solution. Since the beaker is open, the pressure potential is zero.

The water potential of the solution is the sum of the solute potential and the pressure potential:

Y = Ys + Yp

= -7.38 bars + 0 bars

= -7.38 bars.

The water potential of the root tissue (-4.5 bars) is less negative than the water potential of the solution (-7.38 bars), so the net flow of water would be from the solution into the root tissue, moving down the concentration gradient.