EXPERIMENTAL INVESTIGATION 40.1 Does carbon dioxide cause an increase in air temperature?
Equipment Graduated cylinder Water
2 large plastic bottles with a small hole in the cap
Method
1. Use a graduated cylinder to add 250 ml of water to each plastic bottle. Label one of the bottles ‘CO2 tablet’ and label the other ‘No CO2
tablet’.
2. Place a filament bulb on the bench surface and rest a metre stick alongside it so that the bulb is positioned at the 50 cm mark.
3. Place the bottle labelled ‘CO2 tablet’ at the 100 cm mark.
tablet’ at the 0 cm mark and position the bottle labelled ‘No CO2 4. Add two carbon dioxide plant diffuser tablets to the bottle labelled ‘CO2 tablet’ and fit the cap
on top of the bottle. Place the stem of the digital thermometer through the hole in the cap so that the probe is 10 cm above water level. Seal around the hole in the cap with petroleum jelly.
5. Start the timer and record the temperature. 6. Monitor the temperature every 5 minutes for the next 30 minutes and record your observations. 7. Follow steps 4–6 with the bottle labelled ‘No CO2
tablet’. Ideally, start monitoring both bottles at the same time. Digital thermometer
SAFETY • Be careful when punching a hole in the caps of the bottles.
Filament bulb Metre stick
Carbon dioxide plant diffuser tablets
2 digital thermometers Petroleum jelly Timer
Plastic bottle
Filament bulb Water Water
Metre stick Carbon dioxide plant diffuser tablet :Fig. 40.2 To investigate if carbon dioxide causes an increase in air temperature j Go to page 115 of your Experimental Investigations Log to write up this investigation.