Strong Acids and Weak Acids

• What is the pH of an aqueous solution formed by an acid?


  Less than seven
• Why do acids form solutions with a pH of less than seven?


  Because they ionize in aqueous solutions to release hydrogen ions
• What ions does hydrochloric acid dissociate into?


  $H^+$ and $Cl^−$
• What is the ionization product of nitric acid?


  A hydrogen ion and a nitrate ion
• What defines strong acids?


  They ionize completely in solution
• Name two examples of strong acids.


  Hydrochloric acid and nitric acid
• How do weak acids differ from strong acids in terms of ionization?


  Weak acids do not fully ionize in solution
• Give examples of weak acids.


  Ethanoic acid, citric acid, and carbonic acid
• What does it mean for the ionization of a weak acid to be reversible?


  There is an equilibrium between undissociated and dissociated forms
• What does the double arrow in the dissociation equation of ethanoic acid indicate?


  That the reaction is reversible
• What does it mean when we say the equilibrium lies to the left for weak acids?


  There are more undissociated acid molecules than dissociated ones
• How is acid strength different from acid concentration?


  Strength refers to ionization, while concentration refers to the amount of acid in a volume
• What does concentration measure in relation to acids?


  How much acid is present in a certain volume
• Can strong acids be found in both high and low concentrations?


  Yes, strong acids can exist at both high and low concentrations
• Can weak acids also be concentrated or dilute?


  Yes, weak acids can be either concentrated or dilute
• What does pH measure?


  The concentration of hydrogen ions in a solution
• How does the relationship between hydrogen ion concentration and pH work?


  As hydrogen ion concentration increases, pH decreases
• What does a decrease of one on the pH scale represent in terms of hydrogen ion concentration?


  An increase in hydrogen ion concentration by a factor of 10
• If the pH changes from 5 to 3, how much does the hydrogen ion concentration increase?


  By a factor of 100
• If the pH changes from 8 to 11, how does the hydrogen ion concentration change?


  It decreases by a factor of 1,000
• What is required to achieve a low pH with a strong acid?


  A high concentration of hydrogen ions
• Why does a strong acid like hydrochloric acid achieve a low pH at most concentrations?


  Because each particle dissociates fully
• What must a weak acid like carbonic acid be to achieve a low pH?


  It must be highly concentrated
• At any given concentration, how does the pH of a strong acid compare to that of a weak acid?


  A strong acid will always have a lower pH than a weak acid
• What determines the pH of a solution?


  The concentration of hydrogen ions