Simple Science - digest experiments # 28

The burning of acetone on the wire h5>


To experience needed: copper wire, acetone, glass vessel, a gas burner.

To start with collapse of the copper wire spiral heat the thick it with a gas burner. Meanwhile, in a vessel to pour a little acetone, who immediately begins to evaporate. And we just need a pair of acetone.

With the introduction of the heated copper wire into the vessel with the vapors on the surface of the wire begins to occur, catalytic oxidation of acetone. As a result of the chemical reaction produces a significant amount of heat. This heat is sufficient to heat the copper wire is hot.

Fire foam h5>


To experience needed: a basin of water, liquid soap, propane tank, matches.

Foam experimentally filled with natural gas. When a foam tray burning match, part soap balls destroyed (mainly due to the thermal expansion of the gas in the ball) releasing flammable gas outside. The gas ignited immediately, capturing all the foam. Since the foam itself is made up of water, the heat released during the combustion of methane goes to the evaporation of water, and the rest is heat rushes up and does not burn the experimenter.

Acid fire h5>


To experience needed: sulfuric acid, acetone, potassium permanganate (potassium permanganate), cotton, cup, glass rod, metal stand.

The interaction of potassium permanganate (potassium permanganate) and sulfuric acid produced manganese oxide (VII), water and a sulfate (or hydrogen sulfate) potassium.

Mn2O7 - strong oxidant, in contact with many substances causing inflammation and sometimes burst, because it decomposes into free oxygen and lower manganese oxides at a temperature just above 50 degrees. This temperature is reached in exothermic interaction of sulfuric acid and water.

Wool and 99% consists of cellulose and can oxidize manganese oxide to water and carbon dioxide.

However, in our case the wool needed only for uniform inflow acetone as acetone - flammable substance (flashpoint 19 ° C), but a mixture of air containing 2, 5 to 12%, 8% (by volume) explosive.

Spy ink h5>


To experience needed: citric acid, iodine, cup, water, wood or cotton swab.

To write a coded message, enough to have on hand, citric acid or lemon simple. Wood or cotton swab produce labels, pre obmoknuv tip in citric acid.

To decrypt the message enough to put a piece in a solution of iodine. But if you want to save the message, you can simply iron the iron and its inscription is also manifest.

WARNING

Book with experiments for kids h5>
Coming soon in light of our first book for children simple science, pre-order which is already available. Sure the book will be a good gift for the new year;)

Source: habrahabr.ru/company/gtv/blog/195704/