Final answer:
When boba with 10% sugar is stored in pure water at room temperature, the boba absorbs the water due to osmosis, causing it to swell as it reaches equilibrium with the surrounding water.
Step-by-step explanation:
When boba, which contains approximately 10% sugar, is stored in pure water at room temperature, the process of osmosis begins. Since boba is a higher solute concentration than the surrounding water, water molecules will migrate into the boba to equalize the solute concentrations. This process will continue until equilibrium is reached, resulting in the boba swelling as it absorbs water.
If one were to place sugar cubes in a bowl on a table with a dish of water nearby, one could predict that the sugar would remain relatively unchanged unless the environment was very humid. In a sealed container with a beaker of pure water, the presence of sugar in boba or a sugar cube would lower the vapor pressure of the water in the boba or around the sugar, leading to a scenario where the boba or sugar cubes could absorb additional water vapor over time, depending on the container's conditions.
In summary, the boba in pure water at room temperature would absorb water and swell because water moves from an area of low solute concentration to an area of high solute concentration, a process driven by osmosis.