Plants that thrive in salt water must have internal solutions (inside the
plant cells) that are isotonic with (have the same osmotic pressure as) the
surrounding solution. A leaf of a saltwater plant is able to thrive in an
aqueous salt solution (at \(\left.25^{\circ} \mathrm{C}\right)\) that has a
freezing point equal to \(-0.621^{\circ} \mathrm{C}\). You would like to use
this information to calculate the osmotic pressure of the solution in the
cell.
a. In order to use the freezing-point depression to calculate osmotic
pressure, what assumption must you make (in addition to ideal behavior of the
solutions, which we will assume)?
b. Under what conditions is the assumption (in part a) reasonable?
c. Solve for the osmotic pressure (at \(25^{\circ} \mathrm{C}\) ) of the
solution in the plant cell.
d. The plant leaf is placed in an aqueous salt solution (at \(\left.25^{\circ}
\mathrm{C}\right)\) that has a boiling point of \(102.0^{\circ} \mathrm{C}\).
What will happen to the plant cells in the leaf?