Question

Plot the titration curve of aspartic acid it has a volume of \(100 \mathrm{ml}\) and \(0.1 \mathrm{M}\) when titrated with \(0.1 \mathrm{M}\) KOH? \(p k a 1=2.09, p k a 2=3.86\)

\(\mathrm{pka} 3=9.82 ?\)

Answer 1

No. of moles of aspartic acid = molarity x vol in lts = 0.1 M x 100 l/1000 = 0.01 moles

First No. of moles of KOH added at pKa1 (-COOH group) = 0.01 moles/2.09 = 0.00478 moles = A

Second no. of moles of KOH added at pKa2 (NH₃) = A + No. of moles of aspartic acid = 0.00478 +0.01 = 0.01478 moles = B

Third no. of moles of KOH added at pKa3 (Side chain) = B + No. of moles of aspartic acid = 0.01478 +0.01 = 0.02478 moles

pI = pKa1 + pKa2/2 = 2.09+3.86/2 = 5.95/2 = 2.975

TITRATION CURVE OF ASPARTIe ACID 10 Pko3 182 8. PIe2415 PKaf386 O-o0418 0-op 578 0-02419 O-02. MOLES OF O4- COOH Co0 CA2 CH2 yuc. yt-C-H COOH COOH CH2 Ag° Co0 AA PH28 PHZI