Burning Hydrocarbons

A Preliminary Climate Change Investigation

Introduction

You will be burning a small candle in a closed container and measuring changes in CO2 concentrations. The question to be investigated is, “does the burning of the candle change the carbon dioxide amount of the air?” From this question, formulate a hypothesis prior to doing the investigation, and write your hypothesis on the worksheet portion of this lab.

Investigation

Objectives

In this investigation, you will:

1. Research what wax is and what happens chemically when it burns.

2. Measure CO2 change using a CO2 Gas Sensor when burning wax in a closed container.

Materials

Vernier LabQuest deviceCandleDuct tape

Vernier CO2 Gas SensorLarge bucketLighter

Procedures

1. Turn on the Vernier LabQuest device (press the power button in the upper left corner). Connect the CO2 Gas Sensor to CH 1 on top of the LabQuest device. You may need to plug in the device, as this uses a lot of energy. Select the high setting on the Gas Sensor (0-100,000 ppm).

2. Set up the LabQuest App for data collection.

a. Select “File” from the Main screen (upper left), and then select “New” to reset the application.

b. Use the default time-graph setting of 600seconds (see box labeled “Length” on right side of screen).

3. Place the candle on the counter.

4. Using duct tape, tape a Vernier CO2 Gas Sensor to the inside of the bucket pointing toward the bottom of the bucket (as shown below).

5. On the LabQuest device, press start (lower left, green “Play” button). This will start the data collection. Record the initial CO2 concentration on page 3.

6. Wait 30 seconds before lighting the candle. Once the candle is lit, very carefully place the bucket over the candle setup.

7. When data collection is complete (it will stop collecting automatically after 600 seconds), remove the bucket from the candle. CAREFUL, the bottom of the bucket may be hot.

8. On the LabQuest device, select “Analyze”, choose “Statistics”, and check the box next to CO2. Answer the questions on page 3.

  • Note to me – the metal buckets hold 21 liters of air.

Burning Hydrocarbons, a Preliminary Climate Change Lab- Questions

Name: ______Date ______Period ___ ST#___

  1. Hypothesis:
  1. Independent Variable: ______
  1. Dependent Variable: ______
  1. Initial CO2 concentration: ______ppm. That’s ______% of the atmosphere.
  1. Was the candle still burning after 600 seconds? ______If not, can you tell when it went out by looking at the graph on the LabQuest? If so, how?
  1. For what reason might the candle burn out if left burning in the bucket for a long enough period of time?
  1. What is actually happening during the chemical reaction that we call “fire” as this candle burns? (describe)
  1. What does the graph on the LabQuest look like? Explain why it looks that way.
  1. Maximum CO2 concentration: ______(units?). That’s ______% of the atmosphere.
  1. Where did the atoms come from to make answer #7 bigger than answer #2?
  1. What was the change in ppm of the CO2 measurement as the candle burned?
  1. How does the CO2 concentration at the start of the lab (#2) compare to the average atmospheric concentration for the entire planet? How do you account for the difference?
  1. CONCLUSION: Does the data support your hypothesis? Why or why not? Explain! (use top half of back of page)

1