When a base is introduced into this buffer, which of H2CO3 and HCO3− reacts with the base to maintain the pH of the solution?
HCO3−
H2CO3
H2CO3 is the stronger acid and will react with the strong base.
Thank you
When a base is introduced into a buffer solution, the HCO3- ion typically reacts with the base to maintain the pH of the solution. H2CO3 is a weak acid that ionizes to form H+ and HCO3-. The HCO3- ion can react with the base to neutralize the added OH- ions, preventing a significant change in the pH. This reaction helps to maintain the pH of the buffer solution.
To determine which species, H2CO3 or HCO3−, reacts with the base to maintain the pH of the solution, we need to consider the properties of each species as a conjugate acid-base pair.
In this case, H2CO3 and HCO3− form a conjugate acid-base pair. H2CO3 is a weak acid, and HCO3− is its conjugate base.
When a base is introduced into the buffer solution, it will react with the species that acts as an acid. Since H2CO3 is a weak acid, it is more likely to react with the base to maintain the pH of the solution.
HCO3−, being the conjugate base, will remain in the solution and act as a buffer to resist changes in pH. It can accept protons from the solution if the pH increases or donate protons if the pH decreases, helping to maintain the pH within a certain range.
Therefore, in this buffer system, H2CO3 is the species that reacts with the base to maintain the pH of the solution.