cgier 37

Question 1

— are solutions where the ph varies only slightly when a small amount of acid or base is added to it , it usually contains equal amount of — and —-

Answer 1

• buffer
• weak acid and its conjugate base

Question 2

examples of acid base pairs used in buffer system :

Answer 2

1-CO2 + H20 —> H2C03 —> H+ + HC03- (blood buffer system )
first part: respiratory system
2nd part: carbonic acid
3rd part: bicarbonate ion in the excretory system and its the conjucate base
2- H2PO4- —-> H+ HPO4+2
from dihydorgen phosphate ion to mono hydrogen phosphate ion
3- CH3COOH + H20 –> CH3COO- + H30+
from acetic acid to acetate ion

Question 3

the hendrsons hassekbalch equation relates —-
the formula is:
this equation can be used for —

Answer 3

the [ buffer mixture ] to the pH of the solution
-log [H+] = -log Ka -log weak acid / conjugate base
the -log h is the ph
the -log ka is the pKa so:
pH = pKa -log - log conjucate base / weak acid aka ionised / unionised
this equation can be useful for calculating the concentration required in order to prepare buffer of a certain pH

Question 4

we will have perfect buffer system when —-
useful buffer ranges —

Answer 4

1- weak acid = conjugate base
2- +- 1

Question 5

— is the amount of acid or base a buffer can accept without the pH changing appreciably

Answer 5

bugger capacity

Question 6

the greater the amount of conjugate acid-base pair – resistant they are to change in pH

Answer 6

more resistant

Question 7

greater the concentration — the capacity

Answer 7

higher , we expose our blood w/ more acid than base

Question 8

CEHCK SLIDE 23 , 28 , 30

Question 9

the blood must be maintained at the pH of — the pH of the blood is controlled by — enzyme used:

Answer 9

• 7.4
• bicarbonate buffer system
  ( CO2 + H20 –> H2C03 –> HCO3-+ H+)
• carbonic anhydrize

Question 10

in the carbonic acid-bicarbonate buffer system:
if we add a strong acid:
if we ass a strong base:

Answer 10

1
- the [h+] increases
- the reaction moves to the left forming more carbonic acid
- the carbonic acid is unstable and will decompose rapidly to from carbon dioxide and h20
- the c02 formed can be removed from the blood and exhaled by the lungs
2
- base reacts w/ h+ and produces water
- h+ concentration will decrease
- drives the reaction to the right
- [h] ion stored and blood pH is restored

Question 11

[HCO3-] is — times [ H2CO3] in blood which is why the – buffer system in the blood is better at coping with – in the blood since HC03- is responsible for excess —

Answer 11

10 times , carbonate , acid , h+