12.1.1 Acids and Bases

• According to the Brønsted-Lowry theory, what is an acid defined as?

  A proton donor
• According to the Brønsted-Lowry theory, a base is a species that accepts a proton
• In the Brønsted-Lowry theory, a base accepts a proton.
• What two species make up a conjugate acid-base pair?

  Differ by a proton
• In the reaction between HCl and H2O, HCl acts as the acid
• In the reaction between HCl and H2O, H2O acts as a Brønsted-Lowry base.
• What forms when an acid donates a proton?

  Conjugate base
• When a base accepts a proton, it forms its conjugate acid
• What is a conjugate acid-base pair defined by?

  Proton presence or absence
• When a base accepts a proton, it forms its conjugate acid
• What happens to an acid when it donates a proton?

  Forms a conjugate base
• What is formed when a base accepts a proton?

  Conjugate acid
• Conjugate acid-base pairs differ by the presence or absence of a proton.
• Identify the conjugate base of HCl.

  Cl-
• A conjugate acid-base pair consists of two species that differ by the presence or absence of a proton
• Match the acid with its conjugate base:

  HCl ↔️ Cl-

  NH4+ ↔️ NH3

  H2O ↔️ OH-
• What happens in the reaction between HCl and H2O according to conjugate acid-base theory?

  HCl donates a proton
• Amphoteric substances can act as both acids and bases.
• Key examples of amphoteric substances include water and amino acids
• What is the amphoteric behavior of water demonstrated by?

  Donating and accepting protons
• What happens when strong acids dissolve in water?

  They ionize completely
• Weak acids ionize completely in water.

  False
• According to the Brønsted-Lowry theory, an acid is a species that donates a proton
• What role does a base play in the Brønsted-Lowry theory?

  Accepts a proton
• In the reaction HCl + H2O, which substance acts as the acid according to the Brønsted-Lowry theory?

  HCl
• Match the acid with its conjugate base:

  HCl ↔️ Cl-

  NH4+ ↔️ NH3

  H2O ↔️ OH-
• Amphoteric substances can donate and accept protons
• Water is an example of an amphoteric substance.
• What is the definition of an amphoteric substance?

  Acts as both acid and base
• Amphoteric substances can donate and accept protons
• What is the amphoteric reaction of water when acting as an acid?

  $H_{2}O \rightleftharpoons H^ +$$+$$OH^ -$
• What is the amphoteric reaction of amino acids when acting as a base?

  R - NH_{2} + H^ + \rightleftharpoons R - NH_{3}^ +</latex>
• Water acts as a base when reacting with HCl to form $H_{3}O^ +$.
• What happens to strong acids when dissolved in water?

  They ionize completely
• Weak acids like $CH_{3}COOH$ only partially ionize in water.
• Partial ionization of a weak acid in water establishes an equilibrium.
• What does the Brønsted-Lowry theory define an acid as?

  Proton donor
• The Brønsted-Lowry theory defines a base as a species that accepts a proton.
• In the reaction between HCl and water, water acts as a base.
• Match the species with its role in the reaction between HCl and water:

  HCl ↔️ Acid

  $H_{2}O$ ↔️ Base

  $H_{3}O^ +$ ↔️ Conjugate acid

  $Cl^ -$ ↔️ Conjugate base