Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Below is a titration curve for Lysine. If the titration is done by adding NaOH t

ID: 818658 • Letter: B

Question

Below is a titration curve for Lysine. If the titration is done by adding NaOH to a solution containing 4.098 moles of lysine, how many milliliters (mL) of a 10 M solution of NaOH would you have to add to reach point "C" equivalent? Enter your answer in mL with 2 decimal points. Assume that the amount of NaOH added does not have a significant effect on the final volume of the buffer. How many mL of NaOH

Below is a titration curve for Lysine. If the titration is done by adding NaOH to a solution containing 4.098 moles of lysine, how many milliliters (mL) of a 10 M solution of NaOH would you have to add to reach point "C" equivalent? Enter your answer in mL with 2 decimal points. Assume that the amount of NaOH added does not have a significant effect on the final volume of the buffer. How many mL of NaOH

Explanation / Answer


Lysine is effective a tripotic acid with 3 pKa values

=> it can be represented as H3A


Point A = 1st equivalence point:

H3A + NaOH => H2A- + Na+ + H2O


Moles of NaOH added = moles of H3A = 4.098 mol

Volume of NaOH added = moles/concentration of NaOH

= 4.098/10 = 0.4098 L = 409.80 mL


Point D = 2nd equivalence point

H2A- + NaOH => HA2- + Na+ + H2O


Additional Moles of NaOH added = moles of H2A- = 4.098 mol

Additional Volume of NaOH added = moles/concentration of NaOH

= 4.098/10 = 0.4098 L = 409.80 mL


Point C = halfway to 2nd equivalence point where [H2A-] = [HA2-] and pH = pKa2

Volume of NaOH = volume for 1st equivalence point + (1/2) x additional volume for 2nd equivalance point

= 409.80 + 1/2 x 409.80

= 614.70 mL


Hire Me For All Your Tutoring Needs
Integrity-first tutoring: clear explanations, guidance, and feedback.
Drop an Email at
drjack9650@gmail.com
Chat Now And Get Quote