Final answer:
After 30 minutes of reverse osmosis, Tank A's concentrated solution will have decreased in volume with increased solute concentration as water is moved to a less concentrated side.
Step-by-step explanation:
After the reverse osmosis system has been operating for 30 minutes, the solution in Tank A, which is the more concentrated solution, will have decreased in volume as water molecules are forced through a semipermeable membrane into a less concentrated or pure water side. Reverse osmosis involves applying external pressure greater than the osmotic pressure to drive this process. As a result, the solution in Tank A will become more concentrated as pure water is removed, leaving solutes such as salts behind.