Final answer:
The side of the container that is now at 7 cm is Side A, which originally had a 10% sugar solution. When a selectively permeable membrane separates two solutions of different concentrations, water molecules will move through the membrane from the side of higher water concentration to the side of lower water concentration in a process called osmosis.
Step-by-step explanation:
The side of the container that is now at 7 cm is Side A, which originally had a 10% sugar solution.
When a selectively permeable membrane separates two solutions of different concentrations, water molecules will move through the membrane from the side of higher water concentration to the side of lower water concentration in a process called osmosis. In this case, the 10% sugar solution on Side A has a higher water concentration compared to the 40% sugar solution on Side B, causing water to move from Side A to Side B.
As Side A loses water molecules, its height decreases, while Side B gains water molecules and its height increases.