Effect of room temperature on the burn-rate of a candle burns
The materials required for this science fair project:
- 15 candles. The candles should be of the same diameter, length and be made by the same manufacturer
- A ruler
- A caliper
- A stopwatch
- A match box or lighter
- A room with air-conditioning (preferably reverse-cycle)
- A heater (if reverse-cyle air-conditioning is not avaiable)
- A thermometer
1. For this science fair project, the independent variable is the temperature of the room, i.e. 20°C, 25°C and 30°C. The dependent variable is the length of the candle after it has burned for 30 minutes. This is determined by measuring the length of each candle with a ruler before it is lit and after it has burned for 30 minutes. The constants (control variables) are the type and length of the candle, the diameter of the candle and the time the candle is allowed to burn.
2. Using the ruler and caliper, the length and the diameter of the 15 candles are measured for consistency. If the measurement of a candle deviates by more than 1 millimeter from the average, have that candle replaced. All 15 chosen candles are labeled as “A1” to “A5”, “B1” to “B”5 and “C1” to “C5” respectively. The length of the 15 candles is measured and recorded.
3. The air conditioner in the room is switched on and the room is left to is cool, until the room temperature measures 20°C. The temperature of the room is verified with the thermometer. The candles marked “A1” to “A5” are lit in the room and the stopwatch is started. Ensure that windows are closed and the candles are not placed anywhere near the air-conditioner blower (avoid drafts). After 30 minutes, the flames on the candles are extinguished and the length of each candle is measured again with a ruler. The reduction in candle length is calculated and recorded in the table shown below. You may need to air the room to get rid of the candle smoke, before proceeding to step 4.
4. The air conditioner is switched off and the room temperature is allowed to rise to 25°C. You may need to turn on the heater to achieve this temperature. The temperature of the room is verified with the thermometer . Procedure 3 is repeated using the candles marked “B1” to “B5”. The reduction in candle length after 30 minutes is calculated and recorded in the table shown below. You may need to air the room to get rid of the candle smoke, before proceeding to step 5.
5. The heater is turned on in the room until the room temperature reaches 30°C. The temperature of the room is verified with the thermometer. Procedure 3 is repeated with candles marked “C1” to “C5” and the reduction in the candle length after 30 minutes is calculated and the results recorded. in the table below.
Take the necessary precautions when handling fire. Ensure that no flammable materials are placed near the candles during the experiment. Adult supervision required.