Na+

Na+

Na+Cl-

Cl-

Cl-

NaCl solid

salt

NaCl (aq) = Na+ = Cl-

Aqueous Solution(ions dissociate)

Ions in Solution

After mixing Saltwater solution

Water molecule

Chloride ion, Cl-

Sodium ion, Na+

Before mixing Fresh water

Water molecule

Electrolytes

Timberlake, Chemistry 7th Edition, page 290

ElectrolytesElectrolytes - solutions that carry an electric current

NaCl(aq) Na+ + Cl- HF(aq) H3O+ + F-

Hydronium

Ion

strong electrolyte weak electrolyte nonelectrolyte

Solubility and Precipitates • Solubility is the ability of a compound to be

dissolved in a given liquid (normally water). If it does not dissolve, it is insoluble, and a precipitate forms.

1. Write chemical equation.2. Determine from solubility rules if any

compound(s) formed are insoluble in solution. (Na+, K+, NH4

+, NO3- ions are soluble)

3. If compound(s) are insoluble, use symbol (s) to designate “solid precipitate” is formed.

‘hard’ water

carbonic acid

Step 1: Acid rain is formed

Step 2: Acid rain dissolves limestone

Water softner

H2O + CO2 H2CO3

H2CO3 + CaCO3 Ca(HCO3)2

H2CO3 + MgCO3 Mg(HCO3)2

Step 3: Hard water is heated and deposits scales

Ca(HCO3)2 CaCO3(s) + H2O + CO2

Mg(HCO3)2 MgCO3(s) + H2O + CO2

scales on pipes