Diffusion through the Membranes Sita Damaraju (Fellow) Professional Day at NJIT 16 February, 2011

Applications Biology of all Levels Chemistry

Diffusion A process that allows ions or molecules to move from a region higher concentration to a region of lower concentration until equilibrium is attained.

Vernier Experiment ◦ A conductivity probe will be used to monitor ions in solution and monitor its concentration over a period of time. ◦ AIM: Study the effect of concentration gradients on the rate of diffusion. Determine if the diffusion rate for a molecule is affected by the presence of a second molecule.

Materials Computer Vernier conductivity probe Logger pro software Graduated cylinders-3 1%, 5% and 10% salt solutions 400 mL beaker Dialysis tubing 5% sucrose solution Dental floss or clamp Ring stand and utility clamp

DATA Table 1 PredictionConclusion Part 1 Part 2 Part I: When dialysis consisting of salt solution is placed in clean water. (Concentration gradients) Part II: When dialysis tubing consisting of salt solution is placed in sucrose solution. (Effect of other molecules)

Part I: Data Table 2 Salt Concentration (%)Rate of Diffusion (mg/L/s) Table 3 SolutionConductivity Water Sugar water Part II Data

Table 4: Summary of Data SolutionRate of diffusion (mg/L/s) 5% Salt 5% Salt/ 5%sugar Data Summary

Solutions

Part I: Data Table 2 Salt Concentration (%)Rate of Diffusion (mg/L/s) Table 3 SolutionConductivity Water1.5 Sugar water1.9 Part II Data

Table 4: Summary of Data SolutionRate of diffusion (mg/L/s) 5% Salt1.23 5% Salt/ 5%sugar1.21 Data Summary