Practical B5

Investigating the process of osmosis by measuring the change in length or mass of model cells, using Visking tubing.


  • Add sucrose solution to a section of Visking tubing – a selectively permeable substance used to model a cell membrane.
  • Weigh the Visking tubing and its contents.
  • Add the Visking tubing to a beaker of water.
  • Leave for 1 hour.
  • Pat the Visking tubing dry to remove excess water.
  • Reweigh the Visking tubing and its contents.


The Visking tubing will gain mass as water will have moved from an area of high concentration (outside) to an area of lower concentration (inside).