Acids And Bases

• Acids


  Hydrogen-containing compounds that ionize to yield hydrogen ions [H+] in aqueous solution
• Bases


  Compounds that ionize to yield hydroxide ions [OH-] in aqueous solutions
• Common acids


  • HCl
  • H2SO4
  • H3PO4
• Common bases


  • NaOH
  • KOH
• Bronsted-Lowery acid


  Hydrogen ion donor (proton donor)
• Bronsted-Lowery base


  Hydrogen ion acceptor (proton acceptor)
• Bronsted-Lowery base


  • Ammonia (NH3)
• Monoprotic and polyprotic acids

  Acids that produce different numbers of hydrogen ions
• When a hydrogen ion is produced in solution, it immediately attaches itself to a water, forming HYDRONIUM ion (H3O+)
• Arrhenius acid


  Starts with "H"
• Arrhenius base


  Ends with "OH"
• There are organic compounds that can be acids or bases but do not follow the Arrhenius definitions
• Organic acid


  Contains a carboxyl group (-COOH)
• Organic alcohol


  Contains an -OH group but is not a base
• Pure water has a pH of 7, which is neutral because [H+] and [OH-] are equal
• Acidic solution


  [H+] > [OH-]
• Basic solution


  [H+] < [OH-]
• As pH decreases by 1 point, the [H+] increases by 10 times
• As pH increases by 1 point, the [H+] decreases by 10 times
• If pH decreases from 8 to 4


  The [H+] increases by 10,000 times
• Acid (Arrhenius definition)


  Substance that produces only H+ ions in solution
• Base (Arrhenius definition)


  Substance that produces only OH- ions in solution
• Acid (Bronsted-Lowry definition)


  Substance that donates H+ ions
• Base (Bronsted-Lowry definition)


  Substance that accepts H+ ions
• Arrhenius acids


  • HCl
  • H2SO4
  • H3PO4
  • CH3COOH
• Arrhenius bases


  • NaOH
  • KOH
  • Ca(OH)2
  • NH3
• Acids and bases are good electrolytes because they produce ions in solution that can conduct electricity
• Solutions with more H3O+ ions than OH- ions are acidic
• Solutions with a pH of 8 are basic
• Solutions that turn red litmus blue are basic
• Solutions that are clear when phenolphthalein is added are neutral
• Solutions with equal numbers of H3O+ ions and OH- ions are neutral
• Solutions that turn blue litmus red are acidic
• Solutions that are pink when phenolphthalein is added are basic
• Solutions with more OH- ions than H3O+ ions are basic
• Reaction between Ca(OH)2 and H2SO4

  1. Neutralization reaction

  2. Products: CaSO4 + 2H2O
• Salt


  Substance formed when the H+ ion of an acid is replaced by a metal ion
• Salts


  • NaCl
  • Na2SO4
  • Ca(NO3)2
• Neutralization reactions


  1. HCl + NaOH → NaCl + H2O

  2. H2SO4 + 2KOH → K2SO4 + 2H2O

  3. HNO3 + Ca(OH)2 → Ca(NO3)2 + 2H2O
• When a neutralization is complete, the pH of the solution will be 7