L37S10_Polyprotic+Acids,+Amino+Acids+04-23-10

L37S10_Polyprotic+Acids,+Amino+Acids+04-23-10 - Chem 1A L...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Chem 1A L 37: "Polyprotic Acids, Amino Acids " 4/22/2010 Summary Summary TITRATION WEAKWEAK-ACID BASE ©A.Pines,M.Kubinec,UCB L36-1 ChemQuiz© 36.2 Shown Shown in yellow is the is per titration of HNO3 per mole KOH. Which is KOH. Which the the correct curve for x10 dilution of HNO3? A) ©A.Pines,M.Kubinec,UCB H2 O HNO3 B) mol OHmol OH- C) mol OHL36-2 ChemQuiz© 36.3 Shown Shown is in yellow the the titration of HAc per per mole KOH. Which is the KOH. Which correct correct curve for x10 dilution of HAc? HAc? A) ©A.Pines,M.Kubinec,UCB H2 O HAc B) mol OHmol OH- C) mol OHL36-4 ©A.Pines,M.Kubinec,UCB 1 Chem 1A L 37: "Polyprotic Acids, Amino Acids " 4/22/2010 Summary ©A.Pines,M.Kubinec,UCB L37-6 PolyProtic Acids: Indicators Thymol Blue (H2Thy) (H Thy) HThypH pKa2 Thy-2 + H+ pKa2 = 8.8 pKa1 H2Thy HThy- + H+ +OH- pKa1 = 2.0 2.0 a1 ©A.Pines,M.Kubinec,UCB L37-7 PolyProtic Acids H2CO3 pH H3PO4 H2SO4 trend: pKa1 < pKa2 < pKa3 pKa2 pKa1 HCO3H2CO3 +OH- CO3-2 + H3O+ pKa2 = 10.25 HCO3- + H3O+ pKa1 = 6.37 6.37 a1 ©A.Pines,M.Kubinec,UCB L37-8 ©A.Pines,M.Kubinec,UCB 2 Chem 1A L 37: "Polyprotic Acids, Amino Acids " 4/22/2010 ChemQuiz 37.1 Which Which carbonate species is is present in the highest highest concentration at concentration at pH 7 ? pKa2 pKa1 1) 1) H2CO3 ©A.Pines,M.Kubinec,UCB 2) 2) HCO3 -1 3) 3) CO3 -2 L37-9 PolyProtic Acids/Blood Buffer Blood pH Stats: pH PCO = 40 torr 2 pKa2 pKa1 +OH©A.Pines,M.Kubinec,UCB [CO2] = 1.2 mM [CO2] = [H2CO3] Carbonic Anhydrase Kidneys Lungs Henry s Law [HCO3-] = 24 mM L37-11 PolyProtic Acids/Blood Buffer Blood pH Stats: Henry s Law [24] pH = pKa* + log [HCO3 ] pK 6.1 [H2CO3] [CO2] = 1.2 mM [1.2] [CO2] = [H2CO3] [H Carbonic Anhydrase pH pH = 7.40 ± 0.05 [HCO3-] = 24 mM PCO = 40 torr 2 Lungs *at body temperature ©A.Pines,M.Kubinec,UCB Kidneys L37-12 ©A.Pines,M.Kubinec,UCB 3 Chem 1A L 37: "Polyprotic Acids, Amino Acids " 4/22/2010 Amino Acid pKa’s 9.0 +N -O OC C C C C C N + pH = 7.0 10.5 10.1 2. 2 Lysine O 9.1 C C C C C C O C +N 2.2 C C - O Tyrosine ©A.Pines,M.Kubinec,UCB L37-13 Amino Acid pKa’s +N O 10 O C C C 3.9 O 9.2 N C C pH = 7.0 2.0 C O - Aspartic Acid O + C O N C C N N 6.0 C ©A.Pines,M.Kubinec,UCB 1.8 Histidine L37-14 ChemQuiz© 37.2 pKa= 9.0 9.0 What What is the total effective effective charge on on the amino acid cysteine at pH 5.0 ? at N + C C S pK 8.0 pKa= 8.0 C O pKa= 2.2 2.2 Cysteine A) A) + 1 ©A.Pines,M.Kubinec,UCB B) B) 0 C) C) -1 L37-15 ©A.Pines,M.Kubinec,UCB 4 Chem 1A L 37: "Polyprotic Acids, Amino Acids " 4/22/2010 Lecture complete ©A.Pines,M.Kubinec,UCB L37-17 ©A.Pines,M.Kubinec,UCB 5 ...
View Full Document

This note was uploaded on 04/24/2010 for the course CHEM 1A taught by Professor Nitsche during the Spring '08 term at University of California, Berkeley.

Ask a homework question - tutors are online