Question

What is the pH of a solution containing 1.093 mol L^-1 of a weak acid with pK_A = 3.36 and 1.406 mol L^-1 of another weak acid with pK_A = 8.42 ?

You have 5 attempts at this question.

Remember: if you want to express an answer in scientific notation, use the letter "E". For example "4.32 x 10⁴" should be entered as "4.32E4".

Answer 1

To calculate the specific pH of a given buffer, you need to use the Henderson-Hasselbalch equation for acidic buffers: "pH = pKa + log10([A-]/[HA])," where Ka is the "dissociation constant" for the weak acid, [A-] is the concentration of conjugate base and [HA] is the concentration of the weak acid.

The pKa value is one method used to indicate the strength of an acid. pKa is the negative log of the acid dissociation constant or Ka value. A lower pKa value indicates a stronger acid. That is, the lower value indicates the acid more fully dissociates in water.