Each of the following solutions is separated from a solution containing pure water with a semipermeable membrane. Assuming they all have the same temperature, rank the solutions from the highest to the lowest osmotic pressure. Rank the solutions from highest to lowest osmotic pressure. To rank items as equivalent, overlap them: 5.0% KCl, 0.7% KCl, 1.5% KCl, 1.8% KCl, 8.6% KCl.

Osmotic pressure is a measure of a solution's tendency to attract or take in water from another solution when the two solutions are separated by a semipermeable membrane

The order of increasing osmotic pressure is

0.7% KCl 1.5% KCl 1.8% KCl 5.0% KCl 8.6% KCl

Explanation:

Osmotic pressure is the strength of movement of the solvent of a solution through a semipermeable membrane separating solutions of different concentration thereby causing the solvent (such as water) to move from a region of high solute concentration to a region of lower solute concentration.

The amount of osmotic pressure through a semipermeable membrane separating solutions of different concentration is given by

π = i*M*R*T

π = osmotic pressure

i = van't Hoff's factor

(M) = molar concentration

(T) = temperature in kelvin

R = ideal gas constant (0.08206 L atm mol⁻¹K⁻¹)

As seen above, the osmotic pressure is directly proportional to the concentration of the solution thus in the order of increasing osmotic pressure we have

0.7% KCl 1.5% KCl 1.8% KCl 5.0% KCl 8.6% KCl