candles

[mcraig]

Why is it that when you blow out a candle, there is a funny smell, but if you let the candle go out by itself, there is no smell?

Is it maybe something to with carbon dioxide reacting with the flame or something?

[colin6789]

If the candle goes out on its own it has used up all the wax as fuel, if you blow it out the wax vapour will still be there and this may be what you can smell. If you use a candle snuffer or pinch the candle with wet fingers that should leave less of a smell.

[mibn2cweus]

The wax will not burn without a flame to heat it to a gaseous state. The wick lifts the melted wax up into the flame facilitating combustion. The wick burns slowly because oxygen from the surrounding air is depleted in the flame before reaching the wick.

If you blow out the flame oxygen reaches the wick causing it to smolder (the red part in the dark). Without a flame to burn the gases from the smoldering wick, smoke is released into the surrounding air.

If the wick burns too short it can become completely smothered in liquid wax. Deprived of the oxygen in the air the wick cannot smolder.

Candle Burning and Flame