LabBench Activity

Measuring the Rate of Respiration

Gas volume is related to the temperature of the gas. According to the gas law (V=nRT/P) , a change in temperature will cause a direct change in volume. Because the temperature in the respirometers may vary during the course of the experiment, you must correct for differences in volume that are due to temperature fluctuation rather than rate of respiration. To do this, subtract any difference in the movement of water into the vial with glass beads from the experimental vials held at the same temperature. Record the result as the corrected difference.