Osmotic pressure is a colligative property. Which statement best describes it?

Osmotic pressure is a colligative property. Which statement best describes it?

• A. True; depends on the number of solute particles.
• B. False; depends on solute identity.
• C. False; depends on the solvent's color.
• D. False; depends on temperature only.

Answer: (A)

Osmotic pressure is a colligative property, which means it depends on how many solute particles are present in the solution, not on what the solute is. In dilute solutions, osmotic pressure follows π = iMRT, so it increases with solute concentration (M), with temperature (T), and with the effective number of particles produced by the solute (i, the van’t Hoff factor). Because it cares about particle count, two solutions with the same number of dissolved particles exert the same osmotic pressure, regardless of the solute’s identity. The solvent’s color has no influence, and while temperature affects osmotic pressure, it does not negate the dependence on particle number. So the best description is that osmotic pressure depends on the number of solute particles.

Osmotic pressure is a colligative property, which means it depends on how many solute particles are present in the solution, not on what the solute is. In dilute solutions, osmotic pressure follows π = iMRT, so it increases with solute concentration (M), with temperature (T), and with the effective number of particles produced by the solute (i, the van’t Hoff factor). Because it cares about particle count, two solutions with the same number of dissolved particles exert the same osmotic pressure, regardless of the solute’s identity. The solvent’s color has no influence, and while temperature affects osmotic pressure, it does not negate the dependence on particle number. So the best description is that osmotic pressure depends on the number of solute particles.