Electrolytes

Are substances that form positive(+) and negative (-) ions in water Conduct an electric current

Electrolytes in the Body Carry messages send to and from the brain as electrical signals Maintain cellular function with the correct concentrations electrolytes

Strong Electrolytes are 100% ionized salts H 2 O 100%ions NaCl(s) Na + (aq) + Cl - (aq) H 2 O CaBr 2 (s) Ca 2+ (aq) + 2Br - (aq) acids H 2 O HCl(g) H 3 O + (aq) + Cl - (aq)

Weak electrolytes Most of the solute exists as molecules in solution Only a few solute particles produce ions HF + H 2 O  H 3 O + (aq) + F - (aq) acid NH 3 + H 2 O  NH 4 + (aq) + OH - (aq) base

Classification of electrolytes 1.Acids 1.AcidsBinary acids Ternary acids (oxyacids) Thioacids Monoprotic acids Polyprotic acids Strong acids Weak acids

2.Bases 2.BasesMonovalent Polyvalent Strong Weak Basic oxides – base anhydrides Oxides of metals 3.Salts 3.SaltsStrong electrolytes!!!

Important Facts HCl, HNO 3 – strong acids 100% dissociation (no equilibrium, no K) HCl  H + + Cl – 0%HCl, 100% H +, 100% Cl – H + is a proton, a subatomic particle and does not exist alone in solution Really H + + H 2 O  H 3 O + (hydronium ion) HNO 3 + H 2 O  NO 3 – + H 3 O +

Strong electrolytes weak electrolytes conc. of ionic form total concentration  =  ≤  1 Degree of dissociation:  Strong electrolyte:   1 Weak electrolyte:  < 0.5

_ + H H H+H+ H HH H HH O OO O Cl - + _     Conductivity of electrolytes

+ Na + OH - H O H H O H H O H H O H  Conductivity = 1 (  = resistance) 1 cm V = 1 cm 3

 = specific conductivity  cc. NaCl NH 4 Cl H 2 SO 4

Equivalent conductivity:  Conductivity of equivalent amount of electrolyte  =  V V = equivalent dilution in cm 3  inf  = vv  v =   inf = 

cc. ( )  Strong acid Weak acid Weak base Strong base Salt