Acids and bases

• What does the pH scale measure?

  How acidic or alkaline a solution is
• 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?

  Around 2
• What is the pH of acid rain?

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

  Around 9
• What is the pH of bleach?

  Around 12
• What are indicators used for?

  To measure pH by changing color
• What is a wide range indicator?

  Changes color across a wide pH range
• What colors does the universal indicator show?

  Red to bluey purple as pH increases
• How does a pH probe work?

  Measures pH electronically for accuracy
• Why is a pH probe more reliable than an indicator?

  It removes human judgment in measurement
• How is an acid defined?

  Forms solutions with pH less than 7
• What do acids release in water?

  Hydrogen ions
• How is a base defined?

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

  A base soluble in water with pH > 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?

  Produces sodium chloride and water
• How can neutralization reactions be represented?

  In terms of H⁺ and OH⁻ ions
• What is the pH of the products in a neutralization reaction?

  Should be 7, indicating neutrality
• What are some common acids and bases?

  Common acids:

  • Hydrochloric acid
  • Sulfuric acid
  • Nitric acid

  
  

  Common bases:

  • Sodium hydroxide
  • Calcium carbonate
• Why is it useful to learn common acids and bases?

  They frequently appear in various contexts