Determination of Dissociation Constants of Propionic Acid and Lactic Acid (2-hydroxypropionic acid) by Potentiometry and Conductometry

  • SAEEDUDDIN . Shah Abdul Latif Government College Mirpurkhas, Sindh, Pakistan
  • A.W.K. KHANZADA National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan

Abstract

Dissociation constants of propionic acid and 2-hydroxypropionic acid (lactic acid) have been studied at different temperatures between 25 to 50 °C at 5°C interval. Propionic acid is analyzed by conductometry while 2-hydroxypropionic acid is analyzed by potentiometry.  Both investigated compounds are symmetrical carboxylic acids having same length of carbon chain but are markedly different in ionic behaviour. We were interested to see how the hydroxyl group (-OH) induction in propionic acid affects on pKa values of 2-hydroxypropionic acid. We observed that as temperature increases pKa values increases. The increase is observed for both the investigated compounds. pKa values of 2-hydroxypropionic acid are lower as compared to propionic acid because of electron withdrawing group (-OH).

Published
Jun 1, 2004
How to Cite
., SAEEDUDDIN; KHANZADA, A.W.K.. Determination of Dissociation Constants of Propionic Acid and Lactic Acid (2-hydroxypropionic acid) by Potentiometry and Conductometry. Pakistan Journal of Analytical & Environmental Chemistry, [S.l.], v. 5, n. 1, p. 6, june 2004. ISSN 2221-5255. Available at: <http://pjaec.pk/index.php/pjaec/article/view/32>. Date accessed: 22 sep. 2017.