You measure the pH (which is a measure of the [H+], the lower the pH the higher the [H+] is) of a pure water solution and find that it has a pH of 7.0; however, after sitting for a while on the desk, the pH is taken again and found to be 5.7. If this solution is then heated, cooled to room temperature again, the pH is again 7.0. Fully explain these observations. Hint: Remember that when CO2 dissolves in water it produces H2CO3.© BrainMass Inc. brainmass.com October 10, 2019, 5:46 am ad1c9bdddf
Thanks for letting me work on your post. Here is my explanation:
In the air, there is around 0.039% of CO2. When the water ...
This solution explains the pH observations.