A solution with equal concentrations of solute on both sides of a membrane is described as which type?

A solution with equal concentrations of solute on both sides of a membrane is described as which type?

• A. Hypertonic
• B. Hypotonic
• C. Isotonic
• D. Osmotic Pressure

Answer: (C)

Equal solute concentrations on both sides of a membrane define an isotonic situation. In this state, water flows across the membrane at the same rate in both directions, so there is no net movement and the cell’s size remains stable. This balance contrasts with hypertonic conditions, where more solute outside pulls water out and the cell shrinks, and hypotonic conditions, where less outside causes water to enter and the cell can swell or burst. Osmotic pressure describes the force driving water movement due to solute differences, but it is not itself the description of the equal-concentration condition. A practical example: normal saline (about 0.9% NaCl) is isotonic to human cells.

Equal solute concentrations on both sides of a membrane define an isotonic situation. In this state, water flows across the membrane at the same rate in both directions, so there is no net movement and the cell’s size remains stable. This balance contrasts with hypertonic conditions, where more solute outside pulls water out and the cell shrinks, and hypotonic conditions, where less outside causes water to enter and the cell can swell or burst. Osmotic pressure describes the force driving water movement due to solute differences, but it is not itself the description of the equal-concentration condition. A practical example: normal saline (about 0.9% NaCl) is isotonic to human cells.