1. 16.1b: Acid strength and equilibrium position

2.  Strong acids  ionize completely, strong electrolyte  reacts completely with water to form H 3 O +  assume the [H 3 O + ] is equal to the initial acid conc.  shown as >99% over the yield/equilibrium arrow  Strong Acids to know  HCl, HBr, HI, HClO 4, H 2 SO 4, HNO 3 >99%

3.  Weak Acids  compounds with acidic properties that ionizes partially in solution  weak electrolytes  can assume any acid not on the SA list is weak  Ex. acetic acid, lactic acid, citric acid  reacts partially with water to form relatively few H 3 O +  must calculate [H 3 O + ] since small amount of initial acid ionizes  shown as <50% over the yield/equilibrium arrow <50%

4.  acidic:  weak bonds  polar bonds  non-acidic  strong bonds  nonpolar bonds

5.  most make OH - ions  strong bases dissociate into OH - ions and metal ion  Ca(OH) 2  Ca 2+ + 2OH -  LiOH  Li + + OH -  weak bases take a H + from water and make OH -  NH 3 + H 2 O  NH 4 + + OH -  C 6 H 5 NH 2 + H 2 O  C 6 H 5 NH 3 + + OH -

6.  Weak Bases  do not contain OH -  accepts H + from H 2 O to make OH -

7.  also called %rxtn. with water  in acid-base sol’n theory, reaction with water means the same as ionization in water  the higher the conc. of the weak acid sol’n the lower its % ionization  if we know the pH or initial acid conc. of a weak acid solution we can calculate the % ionization

8.  formula p = % ionization [HA] = initial conc. of weak acid

9.  Orange juice has a citric acid concentration of 0.23M and at equilibrium 3.1% has reacted to form H 3 O +. Calculate the [H 3 O + ]  Solution  use formula to solve Plug in and solve for [H 3 O + ]. or

10.  Textbook p721 #2-7, 9, 11, 13, 14