perform a first-hand investigation to demonstrate the effect of dissolved carbon dioxide on the pH of water
Perform your investigation, making sure you take readings of the initial pH of the distilled water.
Basic procedure
Using a data logger with a pH probe, take readings of the change in pH of 100 mL of distilled water as exhaled air is bubbled through it over a two-minute period.
This experiment can also be performed using universal indicator paper and an indicator colour chart to estimate the pH at various stages of the experiment.