Question #96889

1 Answer
Jun 17, 2016

Answer:

See this old answer.

Explanation:

So simply take a weak acid, #HA#, and add approx 1/2 an equiv of sodium hydroxide solution. Alternatively, take the salt of a weak acid, #Na^+A^-#, and again add 1/2 an equiv of strong mineral acid. The #pH# of the solution will remain tolerably close to the #pK_a# of the starting acid.

Given the buffer equation:

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

you should be able to tell me why this is so.