IProposeWe observe osmosis
Links:
capillary tube, osmometer, ring stand, dialisis bag, beaker, funnel, ruler, molasses, distilled water.
Procedure:
1. soak dialysis bag in distilled water for 30 minutes.
2. close one side of the bag up by knotting one end of the bag then tie a string over the knot. (be careful not to spill any molasses or rip the bag)
3. hold the open end of the bag open and fill it up with molasses up to about 1cm from the top using the funnels.
4. Tie the upper end of the bag, with a capillary tube inserted at the top of the bag. (Be careful not to have any air between the molasses and the knot at the tube inserted at the top of the bag)
5. As soon as the osmometer is ready, rinse the outside of the bag to remove excess molasses.
6. Submerge the bag in a beaker containing pure water.
7. As soon as the system is stable, mark the capillary tube with a wax pencil.
8. Observe the dialysis bag to spot molasses leaking from the top or bottom. (If leaking, get more sting and tie it shut where it leaks)
9. When the solution inside of the capillary tube stabilizes, record your observation at time 0.
10. Make observations and mark the solution as it ascends in the capillary tube.
11. Record the change in the capillary column in cm every 10 minutes for a period of 60 minutes.
Safety Precautions:
- Do not fool around near glass objects.
- Do not play with the materials.
Scientific Principles:
1. The molasses solution is being pushed up the glass table due to the pressure from the lower concentration of water.2. Osmosis is the diffusion of water across a membrane.
3. Solutions are isotomic if they contain the same number of solute of a particular kind.
4. A solution is hypertonic with respect to another when it contains more solute of a particular kind than the hypotonic solution.
5. Water diffuses from high concentration to low concentration.
