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 is the most common example of a wide range indicator?

  Universal indicator
• How does universal indicator display pH?

  From deep red to bluey purple
• How is pH measured using a probe?

  By dipping it into a solution
• What is the benefit of using a pH probe?

  More accurate and precise measurements
• How do acids affect pH?

  They release hydrogen ions in water
• What defines a base?

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

  A base that dissolves in water
• What ions do alkalis form in water?

  Hydroxide ions (OH⁻)
• What happens in a neutralization reaction?

  Acid and base produce 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 hydrogen and hydroxide ions
• What is the pH of the products in a neutralization reaction?

  Should be 7, neutral
• What are some common acids?

  Hydrochloric, sulfuric, and nitric acid
• What are common bases?

  Hydroxides and carbonates
• Why is it important to learn common acids and bases?

  They frequently appear in chemistry contexts
• What is the pH scale and its significance?

  • Measures acidity or alkalinity of solutions
  • Ranges from 0 (most acidic) to 14 (most alkaline)
  • Neutral pH is 7 (pure water)
• What are the methods to measure pH?

  1. Using indicators (color change)
  2. Using pH probes (numerical reading)
• What are the definitions of acids, bases, and alkalis?

  • Acids: pH < 7, release H⁺ ions
  • Bases: pH > 7
  • Alkalis: Soluble bases, form OH⁻ ions
• What occurs during a neutralization reaction?

  • Acid + Base → Salt + Water
  • pH of products is 7 (neutral)
• What are some examples of common acids and bases?

  • Common Acids: Hydrochloric, Sulfuric, Nitric
  • Common Bases: Sodium Hydroxide, Calcium Carbonate