Cracking the SAT Chemistry Subject Test

pH  =   4.7 +   log 

Fourth, solve   it.

pH  =   4.7 +   log 

                    =   4.7 +   log 10−1

                    =   4.7 +   (−1)

                    =   3.7

Some Final Facts About Buffers

Here’s another look at the Henderson-Hasselbalch equation, but this time the
concentration terms, M, are expanded into the equivalent (moles/V).

pH  =   log 

Since HA(aq) and A−(aq) are in the same solution, the volumes of both V(HA)

and V(A−) must be equal. Therefore, volume cancels out, leaving