Ions with Distilled Water as an Ambient Environment. Throughout the experiment, different concentrations of a Sucrose and Water solution were placed into hydrolysis tubing and then exposed to a sterile water environment.
An observation was conducted to check for a chemical reaction between starch and iodine, indicating diffusion. Two segments of carrot were observed in distilled and salt water to determine if osmosis was occurring. The purpose was to test the hypothesis that placing various molar concentrations of sucrose and distilled water into an ambient solution of distilled water would cause diffusion into the hydrolysis tubing, resulting in weight gain. Additionally, it was hypothesized that a solution of starch and water in hydrolysis tubing placed in a water/iodine solution would generate a chemical reaction between the starch and iodine, indicating diffusion.
Lastly, two pieces of carrot were used to demonstrate osmosis. One was placed in water and the other in saltwater. The saltwater drew moisture out of the carrot, causing it to become limp. The opposite occurred in the carrot placed in water.
During the experiment, different concentrations of sucrose and water were placed in hydrolysis tubing, which was then placed in sterile water. A starch solution was also observed in sterile water with iodine to check for diffusion. Two segments of carrot were placed in distilled and saltwater to determine if osmosis was occurring between the carrots and the solution.
Materials required: four 5 lengths of hydrolysis tubing, two segments of carrot (sliced lengthways and about 3″ long), four small cups labeled Starch, 1M, .4M, and H2O, iodine, pipette or eyedropper, scales measuring grams, about 5oz of each solution (1M sucrose/water, .4M sucrose/water, distilled water, 50% starch/water), two 30-minute timers, two 20oz open beakers (one filled with distilled water and the other with saltwater, about 15oz), rubber bands or string to tie off tubing.
Procedure:
- Place two lengths of carrot, cut down the middle lengthways, one in a beaker of distilled water and the other in saltwater.
- Fill three lengths of hydrolysis tubing (tied off at one end) with distilled water, .4M solution of sucrose and water, and 1M solution of sucrose and water. Remove all air from the tubes and tie off the other end securely.
- Fill three small cups with distilled water and label with one of the three solutions mentioned earlier.
- Dry the tubing completely and remove excess solution from the exterior. Record the weights of the tubes in grams and place them in their respective cups of sterile water for 30 minutes.
- Tie off another 5″ length of hydrolysis tubing at one end and fill with 10-15ml of a 50% solution of starch and distilled water. Remove all air from the tube and tie off the other end securely. Remove excess starch from the exterior of the bag to prevent diffusion into the ambient solution. Fill another cup with distilled water and add approximately 15 drops of pure iodine. Place the tube with the starch solution into the cup filled with iodine solution and allow it to set for 30 minutes.
- Observe the carrot pieces that were placed into the beakers earlier to determine which, if either, was subjected to osmosis.
