Water Potential

If a cells  $\Psi p$ = 3 bars and its  $\Psi s$ = -4.5 bars, what is the resulting  $\Psi$  ?

• -7.5

• 7.5

• -1.5

• 1.5

The value for  $\Psi$  in root tissue was found to be -3.3 bars.  If you take the root tissue and place it in a 0.1 M solution of sucrose at 20 $\degree$ C in an open beaker, what is the  $\Psi$  of the solution, and in which direction would the net flow of water be?

•  $\Psi s$  = -3.3, net flow into the root

•  $\Psi s$  = 3.3, net flow out of the root (into the solution)

•  $\Psi s$  = -2.43, net flow into the root

•  $\Psi s$  = 2.43, net flow out of the root (into the solution)

NaCl dissociates into 2 particles in water: Na+ and Cl-. If the solution contained 0.1M NaCl instead of 0.1M sucrose, what is the  $\Psi$  of the solution, and in which direction would the net flow of water be (assuming the root tissue is still -3.3bars)?

• -3.3 bars, net flow out of the root (into the solution)

• 3.3 bars, net flow into the root

• -4.87 bars, net flow out of the root (into the solution)

• 4.87 bars, net flow into the root

A plant cell with a $\Psi s$  of -7.5 bars keeps a constant volume when immersed in an open-beaker solution that has a  $\Psi s$  of -4 bars.  What is the cells  $\Psi p$  ?

• -4

• -7.5

• -3.5

• 3.5

At 20 $\degree$ C, a cell containing 0.6M glucose is in equilibrium with its surrounding solution containing 0.5M glucose in an open container.  What is the cell's  $\Psi p$  ? 

• 2.4

• 0.1

• -12.2

• -14.6

At 20 $\degree$ C, a cell with  $\Psi p$  of 3 bars is in equilibrium with the surrounding 0.4M solution of sucrose in an open beaker.  What is the molar concentration of sucrose in the cell?

• 0.4

• -9.7

• -12.7

• 0.5

A cell with a water potential of -1.5 bars is placed in a beaker of sugar water with $\Psi s$  = -4.0 bars.  In which direction will the net flow of water be?

• Out of the cell

• Into the cell

• Both into and out of the cell

• Neither into nor out of the cell

What is the $\Psi s$   of a 1.0M sugar solution at 22 $\degree$ C under standard atmospheric conditions?

• -24.5 bars

• 24.5 bars

• -2.45

• 2.45

At 22 $\degree$ C, zucchini cores are measured and determined to have a sucrose concentration equal to that of 0.36M. What is the $\Psi s$   of these cells and in which direction will the net flow of water be if placed in distilled water?

• 0.64bars net flow of water out of the cell

• -0.36bars net flow of water into the cell

• 8.17 bars net flow of water out of the cell

• -8.83bars  net flow of water into the cell