ch. 2 titration curves of weak acids

the CH₃COOH is the __, and the CH₃COO^- __

conjugated acid; conjugated base

before any base is added to the acid, the pH of the solution is fairly

low

the best buffering capacities of the solutions are

±1 pH units from the pKa

Buffers are

aqueous solutions that tend to resist changes in pH when small amounts of acid or base are added

Buffer DO NOT

prevent changes in pH

Buffers are the effective __ pH unit from pKa

±1

buffer have __ capacities

limited

maximal buffering capacities when

pH=pKa

the ability to prevent changes in pH is directly proportional to the total 

acid and base

a buffer consists of a __ plus its conjugated base

weak acid

a buffer consists of a __ plus its conjugated acid

weak base

What happens to the equilibrium as H⁺ is added?

H⁺¹ reacts with the base and shifts the equilibrium to the left increasing the [H₂PO₄^-1].

What happens to the pH as H⁺ is added?

There still a decrease in pH, since the [HPO₄^-2]/[H₂PO₄^-1] decreases.

The maximum buffer efficiency is when [HPO₄^-2]/[H₂PO₄^-1]   =

1

the only pK relevant at physiological conditions is

6.85