pH scale and indicators

Cards (27)

  • What is acid in water?
    An acidic solution
  • What is a base in water?
    An alkaline solution
  • What is pure water?
    Neutral
  • What are indicators?
    Substances that change colour when added to acidic/alkaline solutions
  • What are the three categories of the pH scale?
    Acid, neutral and alkali
  • What do the red and orange colours of the pH scale indicate?
    Strong acid
  • What do the yellow and light green colours show in the pH scale?
    Weak acid
  • What does green indicate on the pH scale?
    Neutral
  • What does light blue show on the pH scale?
    Weak alkali
  • What does dark blue and purple show in the pH scale?
    Strong alkali
  • What are the numbers that indicate acid on the pH scale?
    0-6
  • What number represents neutral on the pH scale?
    7
  • What numbers represent alkali on the pH scale?
    8-14
  • What does a strong acid do more than weak acid?
    Fizz, float and move
  • Are pH values lower in strong acid than weak acid?
    Yes
  • Is the rate of reaction lower in strong acids than weak acids?
    No
  • Does strong or weak acid have a higher temperature rise than the other?
    Strong
  • What do acidic solutions release in solution?
    H+ ions
  • What are some examples of strong acids?
    • Hydrochloric
    • Nitric
    • Sulfuric
  • What are some examples of weak acids?
    • Ethanoic
    • Citric
    • Carbonic
  • What do alkali solutions contain?
    OH- ions
  • What are some examples of strong alkalis?
    • sodium hydroxide
    • potassium hydroxide
  • What are some examples of weak alkalis?
    • Ammonia
    • Ammonium hydroxide
  • What is a neutralisation reaction?
    When an alkali is added to an acid to neutralise it
  • What is the neutralisation reaction?
    H+ + OH- -> H2O
  • What is a dilute acid?
    Acid molecules mixed with a large amount of water
  • What is a concentrated acid?
    Little to no water molecules mixed with acid