We’re being asked to calculate the pH of a mixture of weak acids containing 5.5×10−2 M in acetic acid and 5.5×10−2 M in hydrocyanic acid.
Remember that weak acids partially dissociate in water and that acids donate H+ to the base (water in this case).
The dissociation of each weak acid is as follows:
**chemical formula of each weak acid can be found in textbooks/online
To solve for the pH of the mixture, we need to do these steps:
Step 1. Determine the weak acid with a higher acid dissociation constant, Ka
Step 2. Construct an ICE table for each weak acid to solve for the concentration of H3O+ from each weak acid
Step 3. Solve for the pH of the mixture
Recall that pH is given by:
Find the pH of each of the following solutions of mixtures of acids.
5.5×10−2 M in acetic acid and 5.5×10−2 M in hydrocyanic acid