Acids & Bases

• Bronsted-Lowry definition

  Acid is a proton donor; Base is a proton acceptor
• Arrhenius definition

  Acids produce $H^+$ions; Bases produce $OH^-$ions
• Acids

  • Tastes sour
  • $pH<7$
  • Litmus is red
  • Phenolphtalein is colorless
  • Methyl orange is red
• Bases

  • Tastes bitter
  • $pH>7$
  • Litmus is blue
  • Phenolphthalein is pink
  • Methyl orange is yellow
• Most acids react with metals, metal oxides, hydroxides, hydrogencarbonates, and carbonates. All these reactions produce a salt which is a compound of an anion and a cation.
• Acid + Hydroxide → Salt + Water
• Acid + Metal oxide → Salt + Water
• Acid + Metal → Salt + Hydrogen
• Acid + Carbonate → Salt + Water + Carbon dioxide
• Acid + Hydrogencarbonate → Salt + Water + Carbon dioxide
• Metal oxide + Water → Base (Metal hydroxide)
• Non-metal oxide + Water → Acid
• Amphiprotic


  A species that can act as both a proton donor and a proton acceptor. Anything amphiprotic is also amphoteric.
• Conjugate base


  A Bronsted-Lowry acid that has donated a proton
• Amphoteric


  A species that can react as both an acid and a base.
• Conjugate acid


  A Bronsted-Lowry base that has accepted a proton
• Ionic product constant of water $K_w$


  $K_w=$$[H^+_{(aq)}]\times[OH^-_{(aq)}]$
• pH formula


  $pH=$$-\log_{10}[H^+_{(aq)}]$