Lecture10 - -5 ). 1) Buffer pH? 2) pH after adding 0.10 mol...

Info iconThis preview shows pages 1–14. Sign up to view the full content.

View Full Document Right Arrow Icon
Common Ion Effect, Buffered Solutions Reading: 15.1 to 15.3 HW: P736 # 9, 11, 15, 17, 21, 23, 27, 31, 35, 37, 39, 45
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Common Ion Effect Have 200 mL 1.0 M HF(aq) (K a = 7.2 x 10 -4 ) 1) [H 3 O + ] 2) pH Add 0.20 mol of KF(s) to solution. 1) [H 3 O + ] 2) pH
Background image of page 2
Common Ion Effect Have 200 mL 1.0 M NH 3 (aq) (K b = 1.8 x 10 -5 ) 1) [OH - ] 2) pH Add 0.10 mol of NH 4 Cl(s) to solution. 1) [OH - ] 2) pH
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Buffers Solutions that are resistant to pH changes (consume both H + and OH - ) Weak conjugate pair in solution HF / F - NH 4 + / NH 3
Background image of page 4
Buffer Action Buffer 1: HF / F - Buffer 2: NH 4 + / NH 3 1) Reaction when H + is added? 1) Reaction when OH - is added?
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Water vs. Buffer
Background image of page 6
Buffer Capacity
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 8
Buffer pH Method 1: Ionization Constant K a = [A - ][H + ] / [HA] , pH = -log [H + ] Method 2: Henderson-Hasselbach equation pH = pK a + log ( [A - ] / [HA])
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
1.0 L of buffer solution prepared with 0.75 M NaCH 3 COO(aq) and 0.75 M CH 3 COOH(aq) (Ka = 1.8 x 10
Background image of page 10
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 12
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 14
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: -5 ). 1) Buffer pH? 2) pH after adding 0.10 mol of HCl? 0.50 L of buffer prepared with 0.50 M NH 3 (aq) and 0.50 M NH 4 Cl(aq). (K a of NH 4 + = 5.6 x 10-10 ) 1) Buffer pH? 2) pH after 0.10 mol HCl added? Have 100 mL of 0.50 M H 2 CO 3 (aq), K a 7.2 x 10-7 . 1) What mass of NaHCO 3 (s) must be added to buffer at pH 6.5? Assume both buffer are made up of same conjugate pair, HA and A-1) Why do both buffers have same original pH? 1) Why does is the pH change for buffers different after NaOH is added? Buffer 1 Buffer 2 Original pH 4.7 4.7 pH after 0.15 mol NaOH added 4.8 6.0 Buffered or Unbuffered? Solution 1: 0.50 mol HCl, 0.50 mol NaOH Solution 2: 0.50 mol HCl, 0.25 mol NaOH Solution 3: 0.50 mol HOCl, 0.50 mol NaOH Solution 4: 0.50 mol HOCl, 0.25 mol NaOH...
View Full Document

This note was uploaded on 08/26/2011 for the course CHEM 104 taught by Professor Quigley during the Spring '08 term at CUNY Hunter.

Page1 / 14

Lecture10 - -5 ). 1) Buffer pH? 2) pH after adding 0.10 mol...

This preview shows document pages 1 - 14. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online