Osmosis Lab Report

By Prince Harmon Jr.


Osmosis, a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one, equalizing the concentrations on each side. The purpose of this investigation was to test that definition. Water was put into a dialysis tube and tied up then placed into a cup of three different types of soda to test is osmolarity of the soda. The independent variable is the solution, while the dependent variable is the water mass, and the controlled variables are the solution, dialysis bags, and amount of solution.


If the water exits the bag then the mass will go down because there are an increased amount of solutes in the cub of soda than there are in the dialysis bag of water.


  1. 3 dialysis bags
  2. 6 pieces of string about 4 in. long
  3. 3 12 ounce cups
  4. 90 ml of drinking water
  5. 200 ml of regular dark soda
  6. 200 ml of diet dark soda
  7. 200 ml of regular clear soda
  8. measuring cups
  9. scale
  10. sharpie marker
  11. funnel


  1. tie bottom of bag with string and fill with 30 ml of drinking water then tie the top of the bag
  2. measure the mass of the bag
  3. add 200 ml of soda and label each cup
  4. add one bag to each cup
  5. let sit overnight in the cups
  6. measure each bag in the morning
  7. collect and record data on a table