and click Add. Record the contents of each diffusion bag for reference later. [Table 2] Determine whether each bag is immersed in a beaker solution that is hypotonic, isotonic, or hypertonic to the FOS Solutions contents of the bag, and specify what the net movement of water will be in each type of beaker solution. 3. Calculate the final percentage of FOS in each diffusion bag. Note that diffusion bag 1 contains undiluted 20% FOS solution. The percent of FOS in the other three diffusion bags can be calculated using the equation:.