AP CHEMISTRY STOICHIOMETRY UNIT NOV 27,2012

AP CHEMISTRY STOICHIOMETRY UNIT

NOV 27,2012

WATER IS ONE OF THE MOST IMPORTANT SUBSTANCES ON EARTH. IT IS ESSENTIAL FOR SUSTAINING REACTIONS THAT KEEP US ALIVE, BUT IT ALSO AFFECTS OUR LIVES IN MANY INDIRECT WAYS.

WHAT ARE SOME OF THE WAYS WATER AFFECTS OUR LIVES?

ELCTROLYTES AND NONELECTROLYTES

LiCl Li+(aq) + Cl-(aq)H2O

(NH4)3PO4 3 NH4+(aq) + PO4 3-

(aq) H2O

WRITING EQUATIONS TO SHOW HOW ELECTROLYTES BREAK UP INTO IONS

STRONG ELECTROLYTES ARE SUBSTANCES THAT COMPLETELY DISSOCIATE IN AQUOUS SOLUTIONS

STRONG ACIDS AND STRONG BASES ARE STRONG ELECTROLYTES

WEAK ELECTROLYTES ONLY PARTIALLY DISSOCIATE IN AQUOUS SOLUTIONS

WEAK ACIDS AND WEAK BASES ARE WEAK ELECTROLYTES

Solvent for Life• Solution– Solute– solvent

• Aqueous solution• Hydrophilic– Ionic compounds

dissolve in water– Polar molecules

(generally) are water soluble

• Hydrophobic– Nonpolar compounds

To perform a dilution, use the formula:

M1V1 = M2V2

where M1 is the molarity of the stock solution and V1 is the volume of the stock solution. M2 is the molarity of the diluted solution and V2 is the volume of the diluted solution.