Acids and Bases

• What does the pH scale measure?

  The pH scale measures how acidic or alkaline a solution is.
• What is the range of the pH scale?

  The pH scale ranges from 0 to 14.
• What pH value indicates a neutral solution?

  A neutral solution has a pH of 7.
• What is the pH of stomach acid?

  The pH of stomach acid is around 2.
• What is the pH of acid rain?

  The pH of acid rain is around 4.
• What is the pH of washing up liquid?

  The pH of washing up liquid is around 9.
• What is the pH of bleach used for cleaning bathrooms?

  The pH of bleach is around 12.
• What are the two main methods to measure pH?

  • Using indicators (chemical dyes that change color based on pH)
  • Using a pH probe connected to a pH meter for electronic measurement
• What is a wide range indicator?

  A wide range indicator is a mixture of dyes that changes color across a wide range of pH values.
• What is the most common example of a pH indicator?

  The most common example of a pH indicator is the universal indicator.
• How does a pH probe measure pH?

  A pH probe measures pH by being dipped into a solution and providing a numerical reading on a meter.
• Why is a pH probe generally more reliable than an indicator?

  A pH probe is more reliable because it removes the need for human judgment in color interpretation.
• How is an acid defined in terms of pH?

  An acid is defined as any substance that forms aqueous solutions with a pH of less than 7.
• What do acids release in water that makes the solution acidic?

  Acids release hydrogen ions in water.
• How is a base defined in terms of pH?

  A base is defined as any substance with a pH greater than 7.
• What is an alkali?

  An alkali is a base that dissolves in water to form a solution with a pH greater than 7.
• What ions do alkalis form in water?

  Alkalis form hydroxide ions (OH^-) in water.
• What happens during a neutralization reaction between an acid and a base?

  • An acid and a base react together
  • Produces a salt and water
  • Example: Hydrochloric acid + Sodium hydroxide → Sodium chloride + Water
• What is the result of the reaction between hydrochloric acid and sodium hydroxide?

  The reaction produces sodium chloride (a salt) and water.
• How can neutralization reactions be represented in terms of ions?

  Neutralization reactions can be represented by H⁺ from the acid and OH^- from the base combining to form H₂O.
• What is the pH of the products in a neutralization reaction?

  The pH of the products in a neutralization reaction should be 7, indicating they are neutral.
• What are some common acids and bases encountered in chemistry?

  Common acids:

  • Hydrochloric acid
  • Sulfuric acid
  • Nitric acid

  
  

  Common bases:

  • Sodium hydroxide
  • Calcium carbonate