04-12-2018, 03:15 PM

I am looking at a question which has the structure of amoxicillin, it asks what % of the compound is ionised at pH3 and it has a pka 2.5.

So using the henderson hasclebalch equation

pH=pKa + log (base/acid) ---> minus pka from both sides

0.5= log (base/acid) ----> take anti log of both sides

3.162/1 = (base/acid) ------> So am I interpreting this correctly, there will be 3.162 x ionised at pH3?

From this how would I calculate percent ionised?

thanks in advance

So using the henderson hasclebalch equation

pH=pKa + log (base/acid) ---> minus pka from both sides

0.5= log (base/acid) ----> take anti log of both sides

3.162/1 = (base/acid) ------> So am I interpreting this correctly, there will be 3.162 x ionised at pH3?

From this how would I calculate percent ionised?

thanks in advance