How can one see diffusion with the help of iodine?
Warning! Under adult supervision.
potassium iodide solution;
Mix copper(II) sulfate and a solution of potassium iodide in a releasable bag. Dip it into a glass of starch solution. Observe the solution gradually turns blue.
When copper(II) sulfate and a solution of potassium iodide are mixed, a redox reaction occurs, releasing iodine. Iodine has a property - it passes through some plastics, like one from which the releasable bag is made of. In this case, it happens due to a process called diffusion.