Determine [OH-] of a solution that is 0.135 M in CO3^2-.

I got 0.00532.

1 answer

When you post a problem like this please include your work and/or what you used for constants; otherwise we can't get the same answer you obtained. I obtained an answer of 0.005 M using k2 of 5.6E-11 so your answer probably is correct.