Acid strength

• Monoprotic acids — contains only one acidic proton (examples, aqueous HNO2, HSO4 –)
• Polyprotic acids — contains >1 acidic proton

  1. Diprotic acids: Composed of two acidic protons
  2. Triprotic acids: Closed of three acidic protons
• Oxyacids — acidic proton is attached to an oxygen atom
• Oxyacids: acidic proton is attached to an oxygen atom
• Hydrohalic acids (HX, where X = F, Cl, Br, or I) — acidic proton is attached to an atom other than oxygen
• Organic acids — contains a carbon backbone, and generally weak acids in nature
• Smaller values of Ka are weaker acids

  *Ka values are unitless
• Amphoteric substance — can behave either as an acid or as a base EX: Water
• [H+] > [OH–] is an acidic solution

  [H+] = [OH–] is a neutral solution

  [H+] < [OH–] is a basic solution
• In all cases, Kw is equal to 1.0 x 10^-14 at 25C
• These two species must be produced in the same concentrations. This is not the case when other acids or bases are present and react with the water.
• Since [OH–] > [H+] (7.8×10-4M versus 1.3×10-11M), the solution is basic.
• Chart

  
• asda

  
• (A-) weak — HA strong

  (A-) strong — HA weak
• If A- is a better (stronger) base than H2O, the value of Ka is less than 1 (weak acid)
• Since equilibrium favors the weaker acid on the product side
• A strong acid HA is completely ionized in water
• A weak acid HB consist of mostly undissociated HB molecules in water