12.5.1 Composition and Function

• What does the Brønsted-Lowry theory define acids as?

  Proton donors
• The Brønsted-Lowry theory defines bases as substances that accept protons
• According to the Brønsted-Lowry theory, acids donate protons and bases accept protons.
• What is the classification of acids and bases based on in water?

  Degree of dissociation
• Strong acids completely dissociate into ions
• Weak acids partially dissociate into ions in water.
• Which of the following is an example of a strong base?

  NaOH
• Arrange the following acids based on their dissociation in water:

  1️⃣ HCl (strong acid)

  2️⃣ CH₃COOH (weak acid)
• A buffer solution resists changes in pH when small amounts of acid or base are added.
• What are the two components of a buffer solution made of acetic acid and sodium acetate?

  Weak acid and conjugate base
• A conjugate base accepts protons (H⁺) to neutralize added acids
• A weak base accepts protons to neutralize added acids.
• A conjugate acid donates protons (H⁺) to neutralize added bases
• Acetic acid in a buffer solution acts as a weak acid while acetate ions act as the conjugate base.
• A buffer solution resists changes in pH
• What is the role of a weak acid in a buffer solution when a base is added?

  Donates protons
• Buffer solutions resist changes in pH by neutralizing added acids or bases
• What chemical equation represents the neutralization of added base in an acetate buffer?

  $CH_{3}COOH +$$OH^{ - } \rightleftharpoons CH_{3}COO^{ - } +$$H_{2}O$
• When acid is added to a buffer solution, the weak acid donates protons
• Adding acid to a buffer solution causes the conjugate base to react and form the weak acid.
• In an acetate buffer, the reaction with added acid is represented by: CH_{3}COO^{ - }(aq) + H^{ + }(aq) \rightarrow CH_{3}COOH(aq)</latex>, where $CH_{3}COO^{ - }$ acts as the conjugate base
• What does the Brønsted-Lowry theory define as an acid?

  Proton donor
• According to the Brønsted-Lowry theory, a base is a substance that accepts protons
• $HCl$ is an example of a substance that donates a proton according to the Brønsted-Lowry theory.
• What is the classification of acids and bases based on their extent of dissociation in water?

  Strong or weak
• Strong acids like $HCl$ completely dissociate
• $CH_{3}COOH$ is an example of a weak acid because it partially dissociates in water.
• Give an example of a strong acid.

  HCl
• Strong bases like $NaOH$ completely dissociate
• $NH_{3}$ is a weak base because it partially dissociates in water.
• What two components are essential for the composition of a buffer solution?

  Weak acid and conjugate base
• Buffer solutions resist changes in pH by neutralizing added acids or bases
• When acid is added to a buffer solution, the weak acid donates protons to neutralize the base.
• What chemical equation represents the reaction of added base in an acetate buffer?

  $CH_{3}COOH(aq) +$$OH^{ - }(aq) \rightarrow CH_{3}COO^{ - }(aq) +$$H_{2}O(l)$