Mixing some of the substances we use in our daily life can have dangerous consequences. For example, if bleach used as a cleaning material and spirit of salt are mixed, it is dangerous to breathe the resulting gas. Some substances can react when mixed, and one of the ways to find this out is to observe if gas is released. We also mixed yeast and hydrogen peroxide with 8th graders and observed how the flame of the stick we lit increased to test the resulting oxygen gas. It was exciting…