EXPERIMENTING WITH DIFFERENT CANDLE WAXES due 3/3

[dragon808]

Hi Science Buddies,

I'm doing a science project on how different candle waxes (Beeswax, Paraffin, Soy, Palm and Coconut) affect a candle's burning time. I've been researching all over the internet and in my local library for books about their melting point. I now know that if it has a lower melting point, then it'll melt faster. I also know that one of the factors that affect melting point is the force of attraction between molecules and Van Der Waals' Forces (the stronger the forces, the higher the melting point). But what I don't know is the molecular structure of these waxes. I haven't been able to find much information about this and I was wondering if you had any ideas or information about this.

Thank you!

[norman40]

Hi dragon808,

The waxes you mentioned are all mixtures of chemicals. None of the waxes have a single molecular structure.

For example, paraffin is a petroleum product composed of hydrocarbons with 20 or more carbon atoms. Most of these hydrocarbons are straight- or branched-chain alkanes. The following link contains more information about the production and composition of paraffin:

https://en.wikipedia.org/wiki/Paraffin_wax

The waxes from plants and bees are mixtures of fats, fatty acids and long-chain alcohols. All of these chemical compounds contain 14 or more carbon atoms. These compounds differ from alkanes in that they all contain oxygen. The following link has some information about the composition and characteristics of several vegetable waxes and oils:

http://www.alafave.org/wp-content/uploa ... xes-EN.pdf

You might want to try searching online for the chemical composition of the specific waxes of interest to you. Also, you might want to take a look at the chemical structures of alkanes, fats, fatty acids and long-chain alcohols. This information should be available online.

I hope this helps. Please ask again if you have more questions.

A. Norman

[dragon808]

Hello A. Norman,

Thank you for your reply Your information and links were very helpful! I just have a question as to whether there are other factors, that involve the wax's chemical composition or structure, that can affect a candle's burning time.

I greatly appreciate your help!!

[norman40]

Hi dragon808,

The burn rate of a candle is determined by the amount of heat released when the wax burns and the rate at which the heat is lost to the surroundings. The chemical composition of the wax can influence both of these factors.

Burning wax in air is an incomplete combustion process that produces a large number of chemicals in addition to carbon dioxide and water. Different by-products (and amounts of them) are produced from various waxes due to their chemical compositions. The types and amounts of by-products influence the heat released (enthalpy).

I ran across a research paper that may be of interest to you. It reports burn rates, combustion products and other details for candles made from paraffin, beeswax and soy:

http://lib3.dss.go.th/fulltext/Journal/ ... 03-808.pdf

I hope this helps. Please ask again if you have more questions.

A. Norman