Question: Calculate the concentrations of H3O(+) and SO4(2-) in a solution prepared by mixing equal volumes of 0.2M HCl and 0.6M H2SO4. (Ka1 for H2SO4 is very large, and Ka2 for H2SO4 is 1.2E-2)
Here is my thought process:
Since the Ka1 for H2SO4 is very large, it will completely dissociate into HSO4- and H3O+. I then used Ka2 to find the equilibrium concentration of HSO4-, H3O+, and SO4(2-) before mixing it with HCl.
When the solutions of equal volumes were mixed, the concentration of each species in both solutions were halved. The concentration of H3O+ is now the sum of the halved H3O+ concentrations from each solution. Since the concentrations have changed, I calculated Qc from the new concentrations and determined that the dissociation equation proceeds to the right.
Lastly, I used Ka2 again to calculate the equilibrium concentrations in the mixed solution.
The final answer I got was [H3O+]=0.40856M and [SO4(2-)]=0.00856M.
I do not have the answer key for this question, so I would greatly appreciate it if you could help verify my thought process/answer. Thank you!