I know this sounds like a silly question but when a candle bought at Yankee Candle burns away, and the jar is empty, is there a waxy coating on the walls of my room? Would one eventually over the years, be able to notice the waxy coating in the room? Are we breathing in wax while the candles burning? I have a lot of questions just like a five-year-old LOL. Someone please help.
In: Chemistry
In our last apartment, we noticed as we were moving out that there was a build up of residue on the walls, especially near the vents. My fiancé worked from home during the pandemic, and likes to burn candles. So a candle was always burning when we were home, for around 16 hours a day, for a year.
Good thing they were painting the walls when we left anyway…
Combustion, that is, burning, is a chemical reaction in which oxygen atoms (O2) bond with the various parts of organic matter (fuel). Organic matter is made up of carbon, oxygen and hydrogen atoms (C2H3O2 or something like that) and, invariably some other stuff (which in the context of fuel would be impurities). Now, it takes a good amount of energy to hold together organic compounds, so when the oxygen rips it apart to bond with its various parts, that energy is released as heat and light.
When the oxygen binds with the carbon and hydrogen atoms in the fuel, it makes carbon dioxide gas (CO2) and water vapor (H2O). If you have a super efficient fuel, the reaction will be complete and that’s all you’ll get (“complete combustion”), but generally, some organic matter will not react and some impurities may be present and that will show up as ash and soot.
In anticipation of the next question, fuel can’t just react with oxygen in the air. It needs heat to break up the organic compounds and allow them to bond with oxygen (“activation energy”) so you need to put a flame to the fuel to light it and then the heat it produces keeps the reaction going (“chain reaction”). The chain reaction will keep the reaction going until a necessary element is removed- fuel, oxygen or heat.
TLDR – a burning candle produces water, carbon dioxide and particles of impurities and incomplete combustion.
If you pay close attention to a candle as it burns, you’ll notice the little waves flowing up from the liquid wax pool around the flame.
If you were to burn a wick with no wax, the thing would burn out straight away. The reason a candle is able to burn for so long is because those little waves I mentioned above are wax vapours that act as a gaseous fuel for the flame and so the wick never burns out until the wax runs out.
The same thing which happens when you burn gasoline, wood, fat, carbohydrates or other hydrocarbons: It combines with oxygen from the air into CO₂ and water. The reaction releases energy (heat).
It’s the same thing when you lose body weight: You use oxygen from the air to burn fat which is exhaled as CO₂ from your lungs.
Fun fact: Plants get most of their solid mass from the air. They are mostly carbon which they get from CO₂. Doing so requires energy which they get from the sun via photosynthesis.
Candle wax is made up from molecules called hydrocarbons. These molecules are made up of long chains of carbon atoms with hydrogen molecules bonded to the carbons. When combusted with oxygen these molecules are turned into carbon dioxide, water and energy in the form of light and heat.
Burned candles literally turn into gas when burned.
Wax is a hydrocarbon. It is comprised of molecules with a long, complex chain of hydrogen and carbon atoms.
Break apart those molecules, combine with oxygen, and you’re left with H2O (water, in the form of water vapor) plus CO2 (carbon dioxide). If the ratio of fuel to oxygen isn’t ideal, you end up with some CO (carbon monoxide) as well.
Water vapor, CO2, and CO are all gasses, so they all end up in the atmosphere.
Latest Answers