CHEM 132, Chapter 13

• Acids


  Sour, react with metals and bases
• Strong acids


  • HCl
  • HBr
  • HI
  • HClO4
  • HNO3
  • H2SO4
• Bases


  Bitter, burns flesh, and react with acids
• Strong bases


  • LiOH
  • NaOH
  • KOH
  • Ca(OH)2
  • Sr(OH)2
  • Ba(OH)2
• Arrhenius acids


  Produce H+ in H2O
• Arrhenius bases


  Produce OH- in H2O
• Bronsted-Lowry acids


  Proton (H+) donors
• Bronsted-Lowry bases


  Proton (H+) acceptors
• Lewis acids


  Electron pair acceptors
• Lewis bases


  Electron pair donors
• The conjugate of an acid/base is always on the product side
• When [H+]=[OH-]


  The solution is neutral
• When [H+]>[OH-]


  The solution is acidic
• When [H+]<[OH-]


  The solution is basic
• Acid strength


  Defined by equilibrium position of its dissociation
• With strong acids, equilibrium lies far to the right (Ka>1)
• With weak acids, equilibrium lies far to the left (Ka<1)
• pH


  Measure of acidity
• When pH=7, the solution is neutral
• When pH>7, it is basic
• When pH<7, it is acidic
• In weak acids, [H+] decreases as [HA]0 decreases


  But percent dissociation increases
• Many bases produce OH- ions by reacting with water
• Polyprotic acids


  Acids that can produce more than one proton, dissociate in a stepwise manner, one proton at a time
• Salts


  Ionic compounds where cation is the conjugate acid of a base and the anion is the conjugate base of an acid
• Salts that are conjugates of strong bases and strong acids have no effect on [H+] when dissolved in water
• Highly charged metal cations can also produce acidic solutions
• In hydrohalic acids, a stronger bond is a weaker acid


  Bond strength is due to polarity and distance between nuclei, follows periodic trend for size of an atom