Ch 18 - Buffers Flashcards
What is a buffer?
It is a solution that resists pH changes upon the addition of small amounts of acid or base
The addition of acid to a solution causes it to react with…
HCO3-
The addition of base to a solution causes it to react with…
H2CO3
What happens when we add a small amount of a strong acid to a buffer?
It converts some of the base to the conjugate acid, decreasing the pH of the buffer
What happens when we add a small amount of a strong base to a buffer?
It converts some of the acid to the conjugate base, increasing the pH of the buffer
When is a buffer the most effective?
When the concentrations of acid and conjugate base are equal
The relative concentrations of acid and conjugate should not exceed by what factor?
10
When is a buffer the most effective?
When the concentrations of acid and conjugate base are high
Titration
It’s when the known concentration and known volume of an acid (or base) reacts with a known volume but unknown concentration of base (or acid)
What is an indicator
Substance whose color depends on the pH
Equivalence point
The point in the titration when the number of moles of the acid is stoichiometrically equal to the number of moles of the base
