Osmosis Lab

OSMOSIS LAB BACKGROUND INFORMATION. Dialysis tubing is being used to model a plasma membrane. Isotonic solutions are solutions that have the same concentration of solutes on both sides of the membrane. Hypertonic solutions are solutions that have more solute to the one with less solute. Hypotonic solution are solutions that have less solute to the one with more solute.

RESEARCH QUESTION:which dialysis tubing will gain the distilled water and which one will loss its content?
HYPOTHESIS:if one of the dialysis tubing losses its content then the other one gains the distilled water.

MATERIAL LIST 2-250ml beakers. 25ml distilled water 25ml sucrose solution(sugar) 2 strings. 2 dialysis tubing.

PROCEDURE. Obtain 2 strips of 15cm dialysis tubing. Tie a knot n one end of each piece of dialysis tubing to form 2 bags. Pour 25ml of each of the following solutions into separate bags: a. Distilled water. b. Sucrose(sugar). remove most of the air from each bag by drawing the dialysis bag between two fingers. Tie off the other end of the bag. Leave sufficient space for the expansion of the contents in the bag.(The solution should fill only about one-third to one half of the piece of tubing. Rinse each bag gently with distilled water to remove any solution spilled during the filling. Carefully blot the outside of each bag and record the initial mass. Place each bag in an empty 250ml beaker and label the beaker to indicate the molarity of the solution in the dialysis bag. Now fill each beaker two-thirds full with distilled water. Be sure to completely submerge each bag. Let them stand for 25 minutes. At the end of the 25 minutes remove the bags from the water. Carefully blot and determine the mass of each bag.

TABLE:Dialysis bag results. Contents of dialysis bag | Initial mass | Final mass | Mass difference(+or-) | % change in mass (+or-) | | Distilled water | | | | | | sucrose(sugar) | | | | | |

*to calculate percentage change in mass = final-initial massX100 initial mass