Strong and Weak Acids

• What is a strong acid?

  An acid that completely ionises in water
• Name an example of a strong acid.

  Hydrochloric acid
• What is a weak acid?

  An acid that partially ionises in water
• Name an example of a weak acid.

  Ethanoic acid
• How does acid strength relate to ionisation?

  Stronger acids completely ionise in water
• What is the definition of a strong acid?

  An acid that completely ionises (dissociates) in water to produce hydrogen ions
• What are examples of strong acids?

  Hydrochloric acid, sulfuric acid, nitric acid
• What is the definition of a weak acid?

  An acid that partially ionises (dissociates) in water to produce hydrogen ions
• What are examples of weak acids?

  Ethanoic acid, citric acid, carbonic acid
• What is the difference between acid strength and acid concentration?

  Acid strength is a measure of the proportion of acid molecules that ionise in water, while acid concentration is a measure of the number of acid molecules in a certain volume of water
• How does the pH of a solution change as the acid concentration increases?

  The pH will decrease with increasing acid concentration regardless of whether it's a strong or weak acid
• How does the pH of a solution change as the acid strength increases?

  For a given concentration of acid, as the acid strength increases, the pH decreases
• What is the relationship between pH and hydrogen ion concentration?

  pH = -log₁₀[H⁺]
• How does the hydrogen ion concentration change when the pH changes by a certain amount?

  When the pH of a solution changes by X, then the H⁺ ion concentration changes by a factor of 10⁻ˣ
• What is the relationship between the pH of a strong acid and a weak acid at the same concentration?

  The pH of a strong acid is always less than the pH of a weaker acid at the same concentration
• What is the relationship between acid strength, acid concentration, and pH?

  For a given concentration of acid, as the acid strength increases, the pH decreases
• What are the key differences between strong and weak acids?

  • Strong acids completely ionize in water, while weak acids partially ionize
  • Examples of strong acids: hydrochloric, sulfuric, nitric
  • Examples of weak acids: ethanoic, citric, carbonic
  • Strong acids have a lower pH than weak acids at the same concentration
• How does pH relate to hydrogen ion concentration?

  • pH = -log₁₀[H⁺]
  • When pH changes by X, [H⁺] changes by a factor of 10⁻ˣ
  • Lower pH means higher [H⁺], higher pH means lower [H⁺]
• How do acid strength and acid concentration affect the pH of a solution?

  • For a given acid concentration, stronger acids have lower pH
  • Increasing acid concentration decreases pH, regardless of acid strength
  • Dilute acids have a higher pH than concentrated acids
• What is the general reaction when a metal reacts with an acid?

  The metal forms products
• How does the reaction of a metal with a strong acid differ from a weak acid?

  The products formed are the same, but the pH of the solution will be lower with the strong acid