# Buffer solutions

1. Oct 3, 2004

### josephcollins

Hi ppl, could anyone give me a hint as to how to calculate this:

Calculate the effect of adding 10cm3 of hydrochloric acid of concentration 1M to 1dm3 of a buffer. The buffer is a solution of ethanoic acid(Ka=1.8 * 10^-5 M) at a concentration of 0.1M and sodium ethanoate at 0.1M.

Thanks for any help
Joe

2. Oct 3, 2004

### poolwin2001

use Henderson-Hasselbalch equation:
$$pH=pK_a+log\frac{[A^-]}{[HA]}$$
if in doubt refer