How do you calculate the pH of two acids in a solution? Examlp: a solution is made by adding 50mL acetic acid(Ka=1.76x10-5) to 50mL 1.00x10-3M HCl. What is the Ph of the solution?

Question

How do you calculate the pH of two acids in a solution? Examlp: a solution is made by adding 50mL acetic acid(Ka=1.76x10-5) to 50mL 1.00x10-3M HCl.  What is the Ph of the solution?

DrBob222 · Answer

There is no set formula for this because you can have all kinds of acids together. In this particular case you have HCl (a strong acid that ionizes 100%) and acetic acid (a weak acid that ionizes only about 1%). Also, the strong acid represses the ionization of acetic acid even more. The total H^+ will be the sum of the two; however, one can't calculate the H^+ from acetic acid until you furnish the concn of the acetic acid.