Please help me with this one

How can a mixture of salt water be separated into salt and water

What sources of error may have contributed to the percent yield not being 100 percent? think about things that may have led to inaccurate measurements or where mass of the product could have been lost if this experiment was conducted in a physical laboratory.

Determine the osmotic pressure at 25 °c of an aqueous solution that is 0.028 m nano3. a) 0.685 atm b) 0.0729 atm c) 1.37 atm d) 0.0364 atm e) 2.06 atm