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Chemistry 217: Candle Experiment Lab (Short) Report By:

Purpose: to gain experience with carrying out procedures of home lab experiments. To obtain basic laboratory skills in such of writing observations and a lab report by conducting burning candle experiment and using different methods to see the reaction of a flame when it is re-ignited as well as extinguished. The following equation of a lit candle will be used to represent the experiment: Procedure: the experiment was carried out as outlined in Candle Experiment of the Chemistry 217 Home Lab Manual, pp. 51- 57. Results Part A: Reigniting a Candle 

The wax from the candle becomes vaporized in the form of smoke and thus when lit will follow back to candle wick as fuel

Part B: Water Suck up:  

Oxygen becomes used up in the glass which creates low pressure.

Part C: Extinguishing a Candle with Aluminum Foil 

Heat from flame becomes absorbed and reflected by the aluminum foil which consumed all the oxygen as it pulls it up and is reflected from aluminum foil, thus causing the flame to extinguish due to lack of oxygen

Part D: Candle Condensation: 

Candle creates carbon dioxide by reacting with oxygen while hydrogen reacts with oxygen, producing H2O (in the form of vapour).

Part E: Extinguishing a Candle with Carbon Dioxide 

Carbon dioxide is produced when mixing baking soda with vinegar. When tipping the glass, the CO2 blocks the oxygen from the flame and extinguishes candle.

Answers to Questions: 1. Why did the candle reignite with a match held away from the wick?

The smoke trail created by the flamed wick creates the melted wax vapour. The vapour created by the wax is highly combustible and provided energy needed for the candle to reignite. 2. a. Explain how the candle was extinguished with aluminum foil and carbon dioxide. The aluminum foil does not allow the oxygen to react with the wick in order to produce a flame. The production of carbon dioxide blocks the oxygen from reaching the wick, and with lack of oxygen, a combustion reaction cannot occur .Thus, the candle becomes extinguished. b. Suggest and explain another method to extinguish a candle not already used in Part A of this experiment Another way to extinguish a candle would be to place a glass cup/jar over the flame (without the use of water). This will burn out all the oxygen within the enclosed environment, causing the flame to become extinguished. c. Write out the balanced chemical equation for the reaction that produced the carbon dioxide you used to extinguish the flame CaCO3(s) + 2HCl(aq)  CaCl2(aq) + H2O(l) + CO2(g) 3. What does the formation of water on the aluminum ice sack suggest about the chemistry of a burning candle? When a combustion reaction occurs, a hydrocarbon and oxygen are reacted together to produce carbon dioxide and water. The candle being the hydrocarbon, reacts with the oxygen in the air and the water vapour created condenses into liquid H2O at the bottom of the aluminum sack. 4. a. Suggest a reason why the water is sucked up into the glass jar As the candle becomes extinguished, the cooling of the air in the environment creates a pressure-like vacuum. The pressure difference that is inside the glass and outside it causes the water to raise pressure equivalent to the pressure outside. b. A candle flame will use up oxygen as it burns. However, the consumption of oxygen alone does not explain the observed volume change. What other factor(s) need to be considered? It is to be noted that after the expansion of hot air within the jar, the air becomes cooler around the candle once the oxygen is depleted. This causes the volume of air to decrease and raise the volume of water. A vacuum/suction is created to

reach equilibrium to the pressure surrounding and inside the jar. Therefore, pressure is also a factor as the inside pressure becomes equivalent to the outside one, due to the vacuum, causing the reaction to stop. 5. Explain the difference in shapes of the two flames (Normal candle and the nearly identical candle in micro gravity flame) shown on page 51 of this manual. The normal candle flame’s shape is an effect caused by gravity. Causing hot air to rise and drawing cool air around it, creating buoyancy, making the flame flicker in a teardrop shape. The normal produces CO2, H2O and soot. In the micro gravity flame, the small sphere is created when the oxygen fuel combines in a zone at the tip of it. The micro gravity flame produces CO, CH2O which makes it a ‘cool flame’ and takes a longer period to burn out as compared to the normal flame.

Conclusion: In this experiment, the basics of a combustion reaction can be observed. A burning candle is a simple combustion reaction. The candle itself is the hydrocarbon, and when reacting with oxygen it creates a flame. The flame produces vapours of H2O and CO2. Unused/unburned candle wax also forms into a vapour as a smoke trail which can be used to reignite a candle....