Treason - 23-11-2006 at 16:26
Hi!
Strange to botehr you once again, but I have a doubt about this reaction.
H3C-COOH + NaHCO3 -----> H3C-COONa + CO2 +H2O
As I understand Acetic acid and Sodium bicarbonate are both acids. How can them react to give a salt, insoluble CO2 and pure water, that would have a
pH =7 ?
I know that I have to have a mistake somewhere. Can anyone answer me?
Thank you.
The_Davster - 23-11-2006 at 17:53
Bicarb is amphoteric, it can either act as an acid or as a base. In this case it acts as a base.
It is easier to think of like this:
NaHCO3 +CH3COOH-->NaOOCCH3 +H2CO3
H2CO3-->H2O +CO2
The second reaction occurs because carbonic acid is unstable and decomposes into water and CO2.
It will not have a pH of 7, reisidual H2CO3 will lower the pH, and sodium acetate does undergo a slight reaction with water. Use Ka or Kb to find out
if sodium acetate will make water acidic or basic.