Chemistry Candle Lab

Chemistry Chapter 4
The Candle Lab | |
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Before You Start –
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The scientific process is a systematic way of explaining how events are related to each other in the natural world. Careful observations are the first step in this process. An observation is a fact obtained with the senses.
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You might think that a burning candle is pretty simple. But, if you really look at it, a burning candle turns out to be a rather complex process.
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During this lab investigation, you will observe a burning candle, formulate questions about the process, and
Paraffin is purified from crude oil, and is thus a petroleum product. Petroleum is formed in the Earth in a natural process over the period of millions of years. Paraffin is a mixture of molecules made of carbon and hydrogen. The hydrogen and carbon composition of paraffin is the reason it is classified as a hydrocarbon. Although paraffin is comprised of a variety of different molecules, a typical molecule contains 25 carbon atoms, and 52 hydrogen atoms; we can use this to give us C25H52 as a rough chemical formula for paraffin. Paraffin, like other products from crude oil such as gasoline, diesel, and kerosene, is a hydrocarbon fuel. The burning of any hydrocarbon produces carbon dioxide (CO2), water (H2O), and heat.
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The wick in a candle is typically a braided cotton string. Cotton consists largely of cellulose. Cellulose is the most abundant biomolecule on Earth. It is composed of six carbon (C), ten hydrogen (H), and five oxygen (O) atoms.

Materials Required * 250mL Beaker and/or 500mL Erlenmeyer flask * metric
Write in numbered steps, the apparent process of a candle burning. (Assume the candle is burning.)

2. What substance (the wick or the wax) is the primary fuel for a burning candle? Supply sufficient evidence from your observations to support your answer.

3. What is the identity of the "smoke" that is released when a candle is extinguished? Supply sufficient evidence to support your answer.

4. What is the role of the wick in a burning candle? Supply sufficient evidence to support your answer. 5. The primary elements in a candle are carbon and hydrogen. What happens to the carbon when the candle burns?

Observations and Results

Note that formally observations and results or explanations for the observations are treated separately in a laboratory report. Since these experiments are rather simple, we will note our observations and possible explanations for those observations in tabular form. You can then incorporate this table into the short-report format described in the “Writing Laboratory Reports” section of this manual.

Experiment | Observations | Results and Explanations | A. Reigniting a Candle

| | | B. Water Suck Up

| | | C. Extinguishing a Candle with Aluminum