Buffers

A (a)   contains lots of a weak acid or base and its conjugate which neutralizes added acid or base to maintain pH.

The tendency of a common ion to decrease the ionization of a weak acid

• Le Chatelier's Principle

• Common ion effect

• Buffer

• Ionization

A buffer will maintain pH over a range of

• pK_a ± 10

• K_a ± 1

• pH ± 1

• pK_a ± 1

True or false: to use the Henderson-Hasselbalch equation to calculate pH, the x is small approximation must be valid.

• False

• True

Which combination would not make an effective buffer solution?

• A weak acid and its conjugate base.

• A weak base and its conjugate acid.

• Equal concentrations of a strong acid and a strong base.

• Equal concentrations of a weak acid and a weak base.

What is the primary function of a buffer solution?

• To change the color of the solution based on its pH.

• To conduct electricity more efficiently.

• To maintain a relatively constant pH when small amounts of acid or base are added.

• To increase the reaction rate of chemical reactions.

Which of the following pairs can form a buffer solution?

• HCl and NaCl

What should I use to prepare a buffer with a pH = 8?

Acid K_a

H₃PO₄ 7.2 *10^-3

H₂PO₄^- 6.3 *10^-8

HPO₄^2- 4.2 *10^-13

• H₃PO₄

• K₂HPO₄ + K₃PO₄

• K₂HPO₄ + KH₂PO₄

• K₂HPO₄ + H₃PO₄

The amount of added acid or base a buffer can neutralize and still maintain pH.

• Buffer capacity

• Common ion effect

• Buffer

• Buffer range

Buffer capacity

• Increases as the concentration of buffer components decreases

• Decreases as the concentration of buffer components increases

• Never changes

• Increases as the concentration of buffer components increases