Correct Option
The correct option is Isotonic solutions.
Explanation
Osmotic pressure is a colligative property of solutions, defined as the minimum pressure required to prevent the inward flow of a pure solvent across a semipermeable membrane. When comparing two solutions, they are classified based on their relative osmotic pressures.
Detailed Analysis
- Isotonic solutions: Two solutions are termed isotonic if they possess the same osmotic pressure at a given temperature. When such solutions are separated by a semipermeable membrane, there is no net flow of solvent in either direction.
- Hypertonic solutions: A solution is hypertonic if it has a higher osmotic pressure (higher solute concentration) relative to another solution. Solvent flows into a hypertonic solution from a hypotonic one.
- Hypotonic solutions: A solution is hypotonic if it has a lower osmotic pressure (lower solute concentration) relative to another solution.
- Azeotropic solutions: These are binary mixtures of liquids that have the same composition in the liquid and vapour phases and boil at a constant temperature. This concept relates to distillation, not osmosis.
Key Takeaway
Isotonic solutions have identical osmotic pressures at the same temperature, meaning they have equal molar concentrations of effective solute particles.