P1252109389npACP

1
Fred J. Grieman
Lec. 24 Acid/Base Equilibria Calculations
HW 8 25, 28, 35, 42, 43, 46, 50
2
Bronsted-Lowry Acids Proton Donors Bases
Proton Acceptors
pKa pKw pKa PKb
3
Solution Equilibrium Calculations
V Mi No
Keq ? ci ?
ni ? mi ? Ni
Pay Attention 1) We will use all of
these components, to understand titration.
2) Acidity/Basicity/Buffers all important for
water in the environment
4
Weak Acid!!!
5
Weak Base in H2O Same as with acids, but with Kb
x2 (0.01) 2.2 x 10-11 x 4.7 x 10-7
6
D. Strong/Weak Reaction Equilibria
E.g., OH
HNO2 ? H2O NO2
7
Weak Acid / Weak Base
HA H2O ? A- H3O
Ka(HA) B- H3O ? HB H2O
Ka(HB)-1 HA B- ? A-
HB K ?
H3O A- HB
A- HB Ka(HA) / Ka(HB)
K
HA B- H3O
HA B-

8
What if we add Weak Acid Its Conjugate
Base??Makes a BUFFER Solution Addition of
acid and or base
changes pH very little

• Nature Water Supply? Does this with Carbonates
  CO2
• 
  CaCO3 H2CO3
• Calculate 1 drop (0.1 mL) of 1 M HCl in 250 mL
  H2O (pH 7.0)
• n(H) (0.0001 L) (1 mol / L) 0.0001
  mol
• H (0.0001 mol) / (0.2501 L) 4 x
  10-4 M pH 3.4 !!!
• Lets See What Happens If We Make a Buffer
  Solution
• Well use HNO2 NO2- as an example

9
(No Transcript)
10
(No Transcript)
11
(No Transcript)
12
Chemistry 1a Section 2 Project Groups Fall,
2007
Group 1 2 3 4 5 6 7 8 9 10 11 12 13
Group Name   Chemis-try is Boron    Naked Mole Rats Sugar pants  BaNa2 BaNaNa CoFFe (IV) US    J squared    What Project? Got Goggles?  Party Ani-MOLES  FOGeYS
  Choi, Elaine Conway, Benjamin Glass, Susan Acosta, Cristina Adams, Thomas Aby, Elizabeth Feblowitz, Daniel Deas, Jessica Blume, Alison Kim, Minsoo Pelland, Catherine Caves, Eleanor Golen, Desiree
  Fish, Whitney Drehmel, Daniel Maidman, John Ladd, Joanna Supraner, Adam DiTullio, David Gordon, Samuel Kopelman, Jared Schumacher, Logan Pin, Garrett Tran, James Chan, Tiffany Hokanson,Kenton
  Ruoff, Anna-Marie Zuckerman, Allana Weber, Abigail Lawless, Mark Wilson, Theodore Joo, Janice Ma, Janet   Selsing, Justine Scharr, Alexandra Yano, Nanako Grewe, Kasey