calculate pH if [HS-] = 10-3 M and [S2-] = 10-6 M. So when HS- dissociates, we get:
HS- -> H+ + S2-. I calculated the [H+] concentration to be ~1.2*10-11. Which results in a pH of approximately 10, if you use that pH = -log[H+]. But does this make any sense? I mean, how can some (although very little) [H+] yield a basic solution? Given the very small amount of [H+] I'd rather think the solution is neutral..?