Answer
When a dialysis bag containing pure water is suspended in a beaker of seawater, pure water will move from the bag into the beaker. Small sized solutes (including ions) will diffuse into the bag. This will continue until there is equilibrium between the solutions in the bag and the beaker. If the dialysis membrane were permeable only to water, then all the pure water would move from the dialysis into the beaker. As solutes cannot pass through the membrane, equilibrium will never be attained between the pure water and seawater.
Work Step by Step
When a dialysis bag containing pure water is suspended in a beaker of seawater, pure water will move from the bag into the beaker. Small sized solutes (including ions) will diffuse into the bag. This will continue until there is equilibrium between the solutions in the bag and the beaker. If the dialysis membrane were permeable only to water, then all the pure water would move from the dialysis into the beaker. As solutes cannot pass through the membrane, equilibrium will never be attained between the pure water and seawater.
