What happens when some alkali is added to a buffer solution?

  • Google+ icon
  • LinkedIn icon
  • 590 views

The dissociation of the weak acid ‘HA’ would be shown as:

HA (aq) ⇌ H+ (aq) + A (aq)

Adding alkali will add OH- ions to the solution. These will react with the H+ ions present in the solution, producing water (H2O). As a result, the concentration of Hions will decrease. The system will react to oppose this change, so the position of equilibrium will move towards the side with the H+. Therefore, the position of equilibrium will move to the right (product side). In order to replace the lost H+ ions, some HA molecules will dissociate forming A- ions in the process. This means the fall in H+ concentration is resisted and the pH of the buffer solution remains fairly constant.

Holly D. GCSE Biology tutor, A Level Biology tutor, GCSE Chemistry tu...

About the author

is an online A Level Chemistry tutor with MyTutor studying at Nottingham University

How MyTutor Works

Still stuck? Get one-to-one help from a personally interviewed subject specialist.

95% of our customers rate us

Browse tutors

We use cookies to improve your site experience. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok