What happens when a candle is alight?

Question

explained the difference between a physical and a chemical change.

identified the reactants and the poducts of the reaction.

Answer 1

when a candle is the the fuel ( the wax ) is being oxidised by the oxygen which acts as a sort of ignition as well , think of the fire triangle  

Answer 2

The candle wick is impregnated with wax.

When a flame is applied to the wick, this wax is melted and vaporised...

A physical Change from solid to liquid to gas.

The vapour mixes with air and a combustion reaction with the oxygen

takes place....

i.e...A Chemical Change producing new substances. CO2 gas, H2O vapour, some CO gas (carbon monoxide) and, Carbon solid particles (as soot) seen in the smoky flame. Heat and light is also produced.

The heat from the flame melts and vaporises wax of the main body of the candle. This vapour travels up the wick by convection from the heat of the flame and feeds the flame thus continuing the above Chemical reaction.

Answer 3

Physical change is simply the change from one state to another without change of composition such as the wax melting from a solid to liquid form and resolidifying.

Chemical change is a change at the elemental level. In this case, you have both the wax and the wick burning. The wax is hydrocarbon based so it combines with oxygen in the air to produce carbon dioxide and steam: CxHy + nO2 .....> CO2 + H2O. There will also be some carbon monoxide depending on the supply of air and probably some sulphur dioxide, ammonia and nitrous oxides from impurities in the wax

Answer 4

When a candle is burning the heat of the flame melts a pool of wax which wicks up the candle wick to the top where the heat is great enough to vaporize the wax into a combustible gas.  These are physical changes similar to melting ice to make water and heating the water to make steam.  Air containing oxygen rises to the burning flame and combusts the vaporized wax which is a hydrocarbon.  The products of combustion are oxygen/carbon and oxygen/hydrogen or CO2 plus H20.  Incomplete burning can also result in carbon monoxide or CO or even unburned carbon particles or soot.  Except for soot, these are chemical reactions because atoms (carbon, hydrogen and oxygen) combine to make new molecules (CO, CO2 and H2O).  The hot gases in the flame expand and are buoyant enough to rise permitting more cool air to replenish the flame.  

Answer 5

Physical change is melting of candle or wax(that is basically a Hydrocarbon).

Chemical change is combustion of Hydrocarbon.

Hydrocarbon(C10H22 or higher hydrocarbon)(s)+O2(g)==>CO2(g)+H20(g)

Answer 6

When a candle is lighted, there is a lovely light from which to read old scrolls of parchment about sorcery and witchcraft. There is also a small risk of a nasty burn for over-enthusiastic children. I hope that helped.