Given the properties of atmospheric carbon dioxide, how might the presence of CO2 in the air affect the accurate measurement of acid concentration using an indicator in a natural sample?

Answer and Explanation:

Carbon dioxide (CO₂) dissolves in water and gives carbonic acid (H₂CO₃) which then dissociates first in HCO₃⁻ and then in CO₃⁻. So, its ionization increases the concentration of H⁺ and the solution becomes more acidic. If you measure the pH of a sample by using a colorimetric indicator and then you exhale your CO₂ in the sample, you will see that the indicator changes its color to the correspondent to a acid solution.