I have a question about the explanations of questions 255 and 256 of the chemistry section of the 2016 DAT Destroyer.
For 255:
Is the pka value determined using the Henderson-Hasselbach eqn as such: 9 = pka + log [ (1x10^-5)/ (1x10^0)]? and if so, is the HA 1x10^0 because the question does not indicate any acid added to the solution? I initially assumed the given [OH] was at the equivalence point but would this be incorrect because there is no equal amount of acid?
For 256:
I guessed the pH would be around 5 and therefore got the right answer. However the solution explanation does not explain why the pH would be 5 or 6. Is this a fact that should be memorized or was this derived somehow?
For 255:
Is the pka value determined using the Henderson-Hasselbach eqn as such: 9 = pka + log [ (1x10^-5)/ (1x10^0)]? and if so, is the HA 1x10^0 because the question does not indicate any acid added to the solution? I initially assumed the given [OH] was at the equivalence point but would this be incorrect because there is no equal amount of acid?
For 256:
I guessed the pH would be around 5 and therefore got the right answer. However the solution explanation does not explain why the pH would be 5 or 6. Is this a fact that should be memorized or was this derived somehow?
