CP12 Investigating pH Changes

• What are the two fundamental chemical substances discussed in this material?

  Acids and bases
• Acids taste bitter, while bases taste sour.

  False
• What is the pH range for acids?

  Less than 7
• Bases release hydrogen ions (H⁺) in water.

  False
• pH is a measure of the acidity or alkalinity
• Enzymes function best at specific pH levels

  True
• Acids have a pH range of less than 7.
• Match the acid or base with its example:

  Hydrochloric acid ↔️ HCl

  Sodium hydroxide ↔️ NaOH

  Sulfuric acid ↔️ H₂SO₄

  Ammonia ↔️ NH₃
• Lower values on the pH scale indicate higher acidity.
• A pH indicator is less expensive than a pH meter


  True
• In a pH meter, the electrical potential difference is proportional to the pH
• What do pH indicators use to determine the pH of a solution?

  Chemical dyes
• pH indicators are simple and inexpensive, requiring no equipment for use.


  True
• Solutions with a pH between 0 and 6 are considered acidic
• In what biological systems does pH play a crucial role?

  Enzyme function ||| Blood maintenance
• What compounds are formed when acids and bases neutralize each other?

  Salts and water
• Match the acid or base with its example:

  Hydrochloric acid ↔️ HCl

  Sodium hydroxide ↔️ NaOH

  Sulfuric acid ↔️ H₂SO₄
• The choice between pH meters and pH indicators depends on the specific requirements of the application.
• Match the pH measurement technique with its advantage:

  pH Meters ↔️ Accurate, quantitative measurements

  pH Indicators ↔️ Simple and inexpensive
• What indicates the approximate pH of a solution when using pH indicators?

  Color change
• What type of ion is released by an acid in a solution?

  H⁺
• Bases release OH⁻ ions in a solution.
• Match the acid-base pair with its neutralization reaction product:

  HCl + NaOH ↔️ NaCl + H₂O

  H₂SO₄ + KOH ↔️ K₂SO₄ + H₂O
• To conduct pH change experiments, acid and base solutions should be prepared at desired concentrations.


  True
• Acids react with bases to form salt and water
• Hydrochloric acid reacts with sodium hydroxide to produce sodium chloride and water.


  True
• What should you ensure about acid and base solutions before starting a pH change experiment?

  Desired concentrations
• Stirring ensures complete mixing of acid and base solutions during a reaction.


  True
• Appropriate personal protective equipment includes gloves and goggles
• Tables are ideal for displaying experimental data systematically.

  True
• What does pH measure?

  Acidity or alkalinity
• pH plays a crucial role in chemical reactions and biological processes
• What is the pH range of acids?

  Less than 7
• Acids release hydrogen ions (H⁺) in water, while bases accept hydrogen ions (H⁺) or release hydroxide ions (OH⁻).
• pH plays a crucial role in many chemical reactions and biological processes.
• What is the definition of an acid according to pH theory?

  Releases H⁺ ions in water
• Acids and bases neutralize each other to form salts and water


  True
• What is the range of the pH scale?

  0 to 14
• A pH meter provides a precise and quantitative measurement of pH.
• What is the fundamental difference between a reference electrode and a pH electrode in a pH meter?

  Measures potential difference