After reading the paragraphs below, answer the questions that follow.
Americans spend up to $100 billion annually for bottled water (41 billion gallons). The only beverages with higher sales are carbonated soft drinks. Recent news stories have highlighted the fact that most bottled water comes from municipal water supplies (the same source as your tap water), although it may undergo an extra purification step called reverse osmosis.
Imagine two tanks that are separated by a membrane that is permeable to water, but not to the dissolved minerals present in the water. Tank A contains tap water and tank B contains the purified water. In the reverse osmosis process, pressure is applied to the tap water tank to force the water molecules across the membrane into the pure water tank.
If you shut off the system and pressure was no longer applied to tank A, you would expect the
◦ water to reverse net flow from tank B to tank A.
◦ water to flow in equal amounts in both directions.
◦ net flow of water to be from tank A to tank B.