What is the pH range of Oxalic acid?
2 Answers
justaguide | College Teacher | (Level 2) Distinguished Educator
The acid dissociation constant is a value defined for every acid HA and denoted by Ka = [H+][A-]/[HA]
The acid dissociation constant of oxalic acid is 5.60×10^-2 and 5.42×10^-5. There are two values as oxalic acid is a poly protic acid and has a chemical formula HOOCCOOH.
5.60×10^-2 = [H+][HC2O4-]/[HOOCCOOH]
5.42×10^-5 = [H+][C2O4 2-]/[C2O4H-]
From the Ka value the value of pH can be derived as :
pH = pKa + log[A-]/[HA]
pKa is defined as the negative of the log to the base 10 of Ka, or pKa = -log Ka
At half neutralization the pH of an acid is given by pH = pKa + 0 as log ([A-]/[HA]) = log 1 = 0. For oxalic acid this ranges between –log(5.60×10^-2 ) = 1.25 and –log(5.42×10^-5 ) = 4.267.
iwalkalone | Student, Grade 10 | eNotes Newbie
hey....!!!
frst of all pka is The negative logarithm of the acid dissociation constant, Ka.
Just like the pH, the pKa tells you of the acid or basic properties of a substance.
Oxalic acid has pKa values of 1.27 and 4.27
hope it hepled.....!! :)