Aqueous Reactions and Solution Stoichiometry

Electrolyte- a substance whose aqueous solutions contain ions. Nonelectrolyte- a substance that does not form ions in solution.

When an ionic compound such as NaCl dissolves in water, each ion separates from the solid structure and disperses throughout the solution.

When molecular compounds dissolve in water, the solution consists of intact molecules dispersed throughout the solution.

In precipitation reactions, an precipitate is formed when two compounds are mixed.

The solubility rules are shown in Table 4.1 of your text book. They determine when and what precipitate is formed when aqueous solutions are mixed.

Will a Precipitate Form? Write the balanced molecular and net ionic equation for the following reaction: barium chloride + sodium sulfate 

When writing chemical equations for reactions in aqueous solutions, an equation written in the following form is a complete ionic equation. 2Al(s) + 6H + + 6Br -  2Al 3+ (aq) + 6Br - (aq) +3H 2 (g) Ions that appear in identical forms on both sides of the reaction arrow are spectator ions. If you leave the spectator ions out of the previous reaction, the net ionic equation is: 2Al(s) + 6H+(aq)  2Al 3+ (aq) +3H 2 (g)

Acid and Bases Acids and bases that are strong electrolytes are called strong acids and strong bases. Those that are weak electrolytes are called weak acids and bases. Table 4.2 in your book lists the strong acids and bases.

Summary of Electrolytic Behavior of Common Soluble Ionic and Molecular Compounds Strong Weak Nonelectrolyte Ionic All None None Molecular Strong Weak All other Acids Acids/Bases compounds