Take as many pairs of temperature and pressure readings as possible, but no fewer than three. If dry ice is not easily available, omit the dry ice bath. Have two students perform the procedures in front of the class while other students fill in a data table. Immerse the bulb of the apparatus in each bath allowing about 90 seconds for the temperature to equalize. Make sure that the bath fluid, slurry, or powder completely covers the apparatus.
Hot apparatus causes burns.
Go to Top Precautions Placing a thermometer in an ice bath colder than the low temperature reading limit on the thermometer may cause the thermometer to break. Use caution with hot objects. The contents of the ice salt bath may be allowed to reach room temperature and then flushed into the sink with running water. Unused dry ice may be set into a hood to sublime. All salts will ultimately depress the freezing temperature reached by the mixture.