pH and Buffers

Cards (20)

  • What is a Bronsted-Lowry acid?
    A proton donor
  • What is a Bronsted-Lowry base?
    A proton acceptor
  • What does neutralisation of an acid and a base produce?
    A conjugate acid and a conjugate base
  • General word formula for acid and base neutralisation

    HA(aq) + B(aq) > BH+(aq) + A-(aq)
  • How to calculate pH
    -log[H+]=pH
  • Write the general Ka expression
    [H+][A-]/[HA]
  • How to calculate pKa
    pKa = -log Ka
  • equation for Kw in pure water
    [H+][OH]
  • How to calculate [H+]
    [H+]= 10^-pH
  • What is a buffer?
    A solution that can resist pH change
  • What is in a buffer solution?
    A weak acid and its conjugate base
  • What does monoprotic mean?
    Releases one mole of H+ per mole in solution
  • Describe how buffers work
    -Reduce large change
    -Adding acid/bare would shift the equilibrium
    -Acid/base reacts with OH-/H+ to form water
  • Describe the dissociation of a diprotic acid
    1st dissociation = full
    2nd dissociation = partial
  • Strong acid-strong base pH curve

    Equivalence point = 7
  • Strong acid-weak base pH curve 

    pH of 1-2 to 8-10
  • Weak acid-strong base pH curve 

    pH of 4-6 to 12-14
  • Weak acid-weak base pH curve 

    No equivalence point
  • How is an indicator suitable for a titration based on the titration curve?
    Its end point covers halfway up the equivalence point
  • How can Ph be measured continuously?
    With a pH probe AND a data logger