C21 acids, buffers + bases

Cards (24)

  • the pH scale is logarithmic
  • an acid is a proton donor
  • a base is a proton acceptor
  • acid-base equilibria involve transfer of protons
  • a strong acid/base is one that completely dissociates to ions when in solution
  • a weak acid/base is one that partially dissociates to ions when in solution
  • the pH scale measures hydrogen ion concentration
  • water slightly dissociates
  • KwK_wis derived from the equilibrium constant for the dissociation of water
  • the value of KwK_wvaries with temperature
  • the dissociation constant of a weak acid is represented by KaK_a
  • acid/base titrations involve an acid/base being added to a base/acid until an end point is reached, shown by an indicator
  • a pH curve for a titration has the pH on the y axis and the volume of substance added on the x axis
  • a buffer solution maintains an approximately constant pH despite dilution or addition of small amounts of acid/base
  • acidic buffer solutions contain a weak acid and the salt of that weak acid
  • basic buffer solutions contain a weak base and the salt of that weak base
  • buffer solutions are used for keeping systems regulated in nature, as enzymes require a specific pH otherwise they denature
  • the equation for pKa is pKa = -log(Ka)
  • the equation for Kw is Kw = [OH-][H+]
  • the concentration of OH- ions of a strong base is represented by [OH-]=[XOH]
  • the equilibrium constant for the dissociation of water is represented by [OH-]=[H+]
  • the concentration of H+ ions of a strong acid is represented by [H+]=[HA]
  • the equilibrium constant of a weak acid is represented by Kc = [H+][A-]/[HA]
  • the equation for pH is pH = -log[H+]