What happens to the water concentration in a compartment with higher osmolarity compared to one with lower osmolarity?

In a system where one compartment has higher osmolarity compared to another with lower osmolarity, the concentration of water in the compartment with higher osmolarity actually decreases. This is because osmolarity refers to the total concentration of solute particles in a solution. When a compartment has higher osmolarity, it contains a greater concentration of solutes compared to the other compartment.

As a result, water will move from the area of lower osmolarity (where solute concentration is lower and, therefore, water concentration is higher) to the area of higher osmolarity (where solute concentration is higher and water concentration is consequently lower) in an attempt to balance the concentrations of solutes across the compartments. This movement of water is driven by osmosis, aiming to achieve equilibrium between the compartments. Hence, in the compartment with higher osmolarity, the effective concentration of water decreases as water moves in response to the osmotic gradient.