4.2.4.1 Understanding the pH scale: 0 (most acidic) to 14

• What is the pH scale used for?

  To measure acidity or alkalinity
• What is the pH of pure water?

  7
• What does a pH of 7 signify about a substance?

  It is neutral, neither acidic nor alkaline
• How do acidic, neutral, and alkaline substances differ in terms of pH?

  Acidic: < 7, Neutral: = 7, Alkaline: > 7
• How do acids and alkalis differ in terms of pH?

  Acids have pH less than 7, alkalis greater
• How can you determine if a solution is acidic, neutral, or basic based on its pH value?

  • pH < 7 is acidic
  • pH = 7 is neutral
  • pH > 7 is basic
• What is a characteristic of alkalis?

  They feel slippery and can dissolve fats
• What pH values indicate alkaline substances?

  Greater than 7
• What is the pH value for Tomato Juice?

  4
• What is the condition of substances with a pH less than 7?

  Acidic
• What are the pH ranges and their conditions?

  • 0-6: Acidic
  • Low pH, tastes sour, reacts with metals
  • 7: Neutral
  • Pure water, pH of 7
  • 8-14: Alkaline
  • High pH, feels slippery, dissolves fats
• What is the pH scale?

  • The pH scale is a measure of the acidity or basicity of a solution.
  • It ranges from 0 to 14, with 7 being neutral.
  • Values below 7 are acidic, while values above 7 are basic.
• What are the three main regions of the pH scale?

  • Acidic region (0-6)
  • Neutral region (7)
  • Basic region (8-14)
• What is the pH value for Lemon Juice?

  2
• What is the pH value for Battery Acid?

  0
• What is the pH value for Urine?

  6
• What is the condition of substances with a pH greater than 7?

  Alkaline
• What pH range indicates an acidic substance?

  0-6
• What happens to the pH as a substance becomes more alkaline?

  The pH increases above 7
• What is the range of the pH scale?

  0 to 14
• How do acids generally taste and react?

  They taste sour and react with metals
• What happens to the pH as a substance becomes more acidic?

  The pH decreases below 7
• What is the pH value for Toothpaste?

  10
• What are the conditions associated with different pH ranges?

  • 0-6: Acidic (e.g., lemon juice, vinegar)
  • 7: Neutral (e.g., pure water)
  • 8-14: Alkaline (e.g., soap, baking soda)
• What is the pH value for Black Coffee?

  5
• What is the pH value for Milk?

  7
• What does a pH of 0 to 14 represent?

  Different levels of acidity or alkalinity
• Why are pH levels significant in everyday life and chemistry?

  They determine how reactive substances are
• What is the pH value for Sea Water?

  8
• What is the pH range of baking soda?

  8-9
• What are the pH values for the different regions of the pH scale?

  • Acidic region: 0-6
  • Neutral region: 7
  • Basic region: 8-14
• What does the pH scale measure?

  How acidic or alkaline something is
• What pH values indicate acidic substances?

  Less than 7
• What pH range indicates an alkaline substance?

  8-14
• What is the pH value for Ammonia?

  11
• What is the pH range of household cleaners?

  10-12
• How do household cleaners work?

  They effectively remove grease and grime
• What is the pH value for Baking Soda?

  9
• What are the pH ranges for acidic and alkaline conditions?

  • Acidic: 0-6
  • Alkaline: 8-14
• What is the effect of alkaline conditions on reactions?

  They can inhibit some chemical reactions