When two liquids are mixed together they produce a lot of foam which looks like toothpaste.
name: Hydrogen peroxide decomposes and oxygen bubbles produce a lot of foam.
This experiment is based on the reaction of hydrogen peroxide decomposition:
2H2O2 → 2H2O + O2
Usually this reaction is very slow. To speed it up the catalyst is added to hydrogen peroxide solution. Potassium iodide participates in the reaction but is not consumed and is recycled:
H2O2 + I- → H2O + IO-
H2O2 + IO- → H2O + O2 + I-
In this case the reaction of hydrogen peroxide decomposition begins and proceeds with high velocity. A lot of oxygen is released and its bubbles cause formation of foam.