pH and indicators

• K₁


  Equilibrium constant for self-ionisation of water
• Ionic Product of Water

  K₁ = [H+][OH-]
• Calculate pH of strong acid


  1. Find [H+] molarity

  2. If [H+] = 10^-5 M, double it

  3. Find [H+] inverse = 10^-pH
• Limitations of pH scale


  • Only has a range of 0-14
  • Does not work for concentrated solutions
  • Only works for aqueous solutions
• Strong Acid vs Strong Base Titration

  1. Find equivalence point

  2. Use methyl orange or phenolphthalein indicators
• Acid


  Proton donor
• Base


  Proton acceptor
• Bronsted-Lowry


  Acid-base theory
• Arrhenius


  Acid-base theory
• Weak Acid vs Strong Base Titration

  1. Find equivalence point

  2. No obvious equivalence point, no indicator
• Weak acid


  pH = -log√(Ka * [HA])
• Weak base


  pH = 14 - (-log√(Kb * [B]))