Well, there is one experiment where I will create an invisible fire extinguisher using sodium bicarbonate (or baking soda) and vinegar to create carbon dioxide gas (although I know that they're used for volcano or bubbly projects and stuff, but I didn't do that). Another experiment I did is creating a ph indicator using sodium carbonate (again), water, and Phenolphthalein, in which the mixture will turn into a shade of red. And then, I decolorize it by either blowing carbon dioxide using a straw or pouring an acid such as vinegar.
...And that's pretty much it. Just two as of the meantime.