What is the white smoke produced when the candle goes out? The white smoke produced when the candle is extinguished is small white particles formed by solidification of paraffin wax. There are two changes in wax combustion, the first is physical change: solid wax is liquefied by heating, and then vaporized into waxy gas molecules dispersed in the air; Then there is chemical change: gaseous wax molecules mix with oxygen to produce redox reaction, and CO2 and water are generated.
The phenomenon that a substance burns in oxygen is 1. Iron burns violently in oxygen, and sparks are everywhere, generating black solids, releasing a lot of heat and generating ferroferric oxide.
2. Sulfur emits a blue-purple flame in oxygen, producing a pungent gas, releasing a lot of heat, producing a light blue flame in the air, producing a pungent gas and releasing a lot of heat.
3. Carbon burns in oxygen: it emits bright white light and produces a gas (CO2), which can make clear limewater turbid.
4. Hydrogen burns in oxygen: a light blue flame is generated; Emit heat; Cover a dry beaker above the flame, and there are water droplets on the wall of the beaker.
5. Phosphorus burns in oxygen: it produces a lot of white smoke (P2O5).
6. Sodium burns in oxygen: it gives off a yellow flame and generates a yellow solid (Na2O2 sodium peroxide).
7. Copper is heated in oxygen: the solid changes from red to black (CuO).
8. Methane burns in oxygen: it emits a light blue flame, producing carbon dioxide and H2O.