Acids and bases

• What does the pH scale measure?


  The acidity or alkalinity of a solution
• What is the pH range of the scale?


  0 to 14
• What pH value indicates a neutral solution?


  7
• What is the pH of stomach acid?


  Approximately 2
• What is the pH of acid rain?


  Approximately 4
• What is the pH of washing up liquid?


  Approximately 9
• What is the pH of bleach?


  Approximately 12
• What are indicators used for in measuring pH?


  They change color depending on the pH level
• What is a wide range indicator?


  An indicator that changes color across a wide range of pH values
• What is the most common example of a wide range indicator?

  Universal indicator
• How does a pH probe measure pH?


  By dipping the probe into a solution and electronically measuring the pH
• Why is a pH probe more reliable than an indicator?


  It removes the need for human judgment
• How is an acid defined in terms of pH?


  Any substance that forms aqueous solutions with a pH of less than 7
• What do acids release in water?


  Hydrogen ions
• How is a base defined in terms of pH?


  Any substance with a pH greater than 7
• What is an alkali?


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


  Hydroxide ions (OH^-)
• What is produced in a neutralization reaction?


  A salt and water
• What is the reaction between hydrochloric acid and sodium hydroxide?


  Hydrochloric acid + Sodium hydroxide → Sodium chloride + Water
• How can neutralization reactions be represented in terms of ions?


  H⁺ from the acid and OH^- from the base combine to form H₂O
• What is the pH of the products in a neutralization reaction?


  7, because they are neutral
• What are some common acids and bases?

  Common acids:

  • Hydrochloric acid
  • Sulfuric acid
  • Nitric acid

  
  

  Common bases:

  • Sodium hydroxide
  • Calcium carbonate
• What is the significance of learning common acids and bases?


  They frequently appear in various contexts
• What is the main purpose of the video discussed?

  To explain the pH scale and the nature of acids and alkalis
• What is the relationship between pH and the acidity of a solution?


  Lower pH values indicate higher acidity
• What happens to the pH as a solution becomes more alkaline?


  The pH value increases
• How do acids and bases interact in a neutralization reaction?


  They react to form a salt and water