The Science Behind Candles

         The Science Behind Candles


Candles are a beautiful creation of science. Not only does it light up its surroundings, but also creates an ambiance. It enlightens the mood and makes every place appear better due to its commanding light or fragrance. However, what goes on behind the scenes in a candle should also be known, so that we all know how candles work and how to make the best use of them.

There are some questions that arise in our mind, when we see a melting candle or a lit candle in front of us. Krazykandle is here to answer some of them for you.

How do candles burn? Where candle wax goes? Does wax burn or does it evaporate? What really happens to the wax as your candle burns?

These are all common questions about how a candle works. When we see a lit candle, a lot of us may not pay attention to the wax and how it melts, but do wonder how it produces such a nice scent. The wax itself is the substance that fuels the flame and continues to burn the lit candle.

When you burn a candle, liquid wax is drawn up the wick where burns. This process is called oxidation. As the wax burns, it converts into water vapor and carbon dioxide. Which in turn releases heat and light. Both water vapor and carbon dioxide are invisible, so you will not see the oxidation process as the wax burns. The heat from the reaction melts more wax, which in turn is drawn up the wick and starts the process over. This continues until you either blow out the flame or there is no more wax.  A fair amount of the wax is being vaporized and released into the air by the heat. The liquid that you see is wax that was heated up enough to melt it, but not enough to vaporize it.

Why is candlelight yellow in color?

A lit candle flame burns at a relatively low temperature. When candles burn, most of the wax reacts with the oxygen in the air to form a mix of water vapor and carbon dioxide. These particles are heated up under the high temperature and glow with a bright yellow light. This makes candlelight yellow. The color of a flame really depending on the temperature. The higher the temperature the more bluish and eventually white is the flame. The temperature of the flame all revolves around the fuel available and the fuel/oxygen ratio. The more oxygen the flame gets, the hotter the flame.

With a lit candle, more fuel is available than there is oxygen in the air. This makes the flame yellowish color. A great example is a fire in a fireplace. If you just burn wood, the flames will range from red to yellow in color. However, if you fan the flames or just blow on the fire, it will take a whiter color. The reason for this is because you are forcing more oxygen to the fire increasing the burning rate and thus the flame temperature.

What type of matter is candle flame?

All three states of matter are involved as far as a lit candle and a melting candle is converned. However, candle flame to be specific, is gaseous in matter. As discussed above, the candle wax melts, pulls up towards the flame and then evaporates in the atmosphere. The evaporated wax is then seen as the flame of the candle, making it a visible gas.

Why do candles blow out when it is windy?

People think that blowing a candle is what puts out the flame. However, winds cannot actually put out fire as it goes totally against the process of combustion. Strong winds are what makes forest fires spread and become so huge. Can they be put out simply by blowing? Absolutely not. This happens because the oxygen in the wind fuels the fire.

When we blow the flame of a lit candle, our breath contains just a little oxygen and more carbon dioxide. But this is not the sole reason why it burns out by blowing. The strong puff, blows away other burning gases around the flame that are needed to keep the flame lit. The particles that are left behind cool down quickly, until they reach a temperature low enough to contain the flame anymore, causing the candlelight to blow out.

Why does a candle’s flame flicker in a closed room?

Flames can flicker due to two major reasons. Firstly, they may flicker because of impurities in the wax of the candle. As mentioned earlier, in the melting candle, the wax is drawn up towards the flame in order to fuel it and keep it lit. Impurities in the wax, at the time of manufacturing or transport may cause flames to flicker.

In a closed room, flames mainly flicker because of the dense air around it. The surrounding of the flame is usually heated, with cooler surroundings. However, when the room is closed, the vapor from the lit candle is less dense than the surroundings, causing it to flicker.

Do candles reduce stuffiness in the air?

Air gets stuffy when it has been breathed into a number of times. This means it has high levels of oxygen and low levels of carbon dioxide. When a candle burns, it reduces the amount of oxygen in the air, to help it with the process of combustion. When the candle wax evaporates into the air, it does not make the quality of air any better. Therefore, it is safe to say that lit candles don’t reduce stuffiness in the air.

Does burning candles make walls dirty?

The smoke from a lit candle is comes from the tiny particles of carbon in the wax that weren't completely burned combined steam. This produces small amounts of black smoky substance from the flame. Over time, if you do not burn your candles properly it can cause build up.  The small amount of soot produced by a candle is the natural byproduct of incomplete combustion and is not considered a health concern. This is similar to the soot given off by kitchen toasters and cooking oils and is chemically different from the soot formed by the burning of diesel fuel, coal, or gasoline. However, there are several things you can do to prevent soot.   Keep your wick trimmed. According to the National Candle Association, one of the absolute best ways to keep soot down when you're burning a candle is to keep the wick trimmed to about ¼".  Make sure your wick is made of cotton, rather than lead wicks.  Keep debris out of your candles, including match sticks, dirt or dust. All of our Custom candles are made with cotton wicks for the best burn!

What happens when you put a lid over a burning candle?

Putting a lid over a lit candle is a very effective way to extinguish a flame. When you cover the flame of the candle, the flame loses oxygen to help it remain lit. Eventually, the flame dies. It is a healthier way to blow out a candle because the black smoke or burnt chemicals remain in the lid and do not contaminate the air. This is a good reason to use container candles to burn your favorite candle. 

At what temperature does candle wax melt?

The melting point of candle wax varies with the different types of wax. However, on average, it melts between 100 to 180 degrees Fahrenheit. Among these, the most common ones are paraffin wax, with a melting point of 122 to 158F, soy wax that melts at 120 to 180F and beeswax, melting at 143 to 151F

The simplicity of a burning candle is a beautiful sight and it may surprise you to learn just how much science is actually taking place behind the scenes. For hundreds of years, experts have been studying the chemistry and physics at work when a candle burns. This article should have taken away some of the mystery of what goes into a candle so that you understand a little more about the science behind how candles work. Now you can go ahead and light your vanilla candle or your pretty pink candle and enjoy it even more. 

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