Why is a buffer solution used?

1 Answer
Feb 6, 2017

Why? Well to prevent GROSS changes in #pH#.

Explanation:

See this old answer.

#pH=pK_a+log_10{[[A^-]]/[[HA]]}#

This expression is derived in the link, along with some of the implications. When you do a titration of a weak acid, the POINT of half-equivalence, i.e. when #[HA]=[A^-]#, which may easily be interpolated from a graph, is the #pK_a# of the acid? Why?