Buffer action Flashcards
1
Q
What is a buffer?
A
A solution that resists changes in pH when small amounts of acid or alkali are added
2
Q
What is the pH of an acidic buffer?
A
Less than 7
3
Q
What does an acidic buffer contain?
A
A mixture of weak acid and its salts
4
Q
How does an acidic buffer resist changes with an acid?
A
- you need a large amount of salt
- If you add a small amount of acid, the H+ concentration increases and most of extra H+ will combine with salt to form acid
- Equilibrium shifts to the left, reducing the H+ concentration back to the original value
5
Q
How does an acidic buffer resist changes with a base?
A
- A large amount of a base is added and OH- concentration increases
- Extra OH- ions react with H+ ions to form water, removing the H+ from the solution
- More CH3CH2COOH dissociates so H+ increases until it is back to normal concentration
6
Q
What is the pH of a basic buffer?
A
pH greater than 7
7
Q
What does a basic buffer contain?
A
a mixture of a weak base and one of its salts
