Sulphuric acid is very stongly dehydrating and will pull water from the propanone's molecular structure to make propene or dipropyl ether, the majority product generally being a function of reaction temperature. Both products are highly flammable, toxic, and can probably form explosive mixtures with air fairly easily. This reaction is somewhat analagous to the extremely exothermic dehydration of sugar by concentrated sulfuric acid to make the familiar column of bubbly-looking carbon.