Acids and bases

• pH scale


  Measure of how acidic or alkaline a solution is, ranging from 0 to 14 with low numbers being most acidic and high numbers being most alkaline
• Neutral pH is 7, which is neither acidic nor alkaline
• pH indicators


  • Chemical dyes that change color depending on the pH
  • Wide range indicators like universal indicator change color across a wide range of pH
• pH meter


  Electronically measures pH, more accurate and precise than indicators
• Acid


  Substance that forms aqueous solutions with a pH less than 7, releases hydrogen ions in water
• Base


  Substance with a pH greater than 7
• Alkali


  A soluble base that forms a solution with a pH greater than 7, forms hydroxide ions in water
• Neutralization reaction


  1. Acid + base → salt + water

  2. H+ from acid + OH- from base → H2O
• Common acids


  • Hydrochloric acid
  • Sulfuric acid
  • Nitric acid
• Common bases


  • Sodium hydroxide
  • Calcium carbonate