Acids + bases

• pH

  • Measures how acid/alkali a solution is
  • 0 - 15
• 2 ways to measure PH

  • Universal indicator
  • pH probe and meter
• pH probe and meter is more precise and accurate
• Acid

  Any substance that forms an aqueous solution with pH less than 7
• What do acids release that make them acidic?

  they release hydrogen ions in water
• Bases

  • Any substance with pH greater than 7
  • An alkali is a sub-group of bases soluble in water
• Alkali

  Base that dissolves in water to form a solution with pH greater than 7
• What do alkali‘s release that make when alkaline?

  they release hyrdroxide ions
• What happens when an acid and alkali react together?

  • Forms neutralisation reaction
  • Always produces salt + water
• Example of acids

  • Nitric acid
  • Hydrochloric acid
• Example of bases

  • Calcium carbonate
  • Sodium hydroxide