Solutions

Definitions

Solution: homogeneous mixture of 2 or more substances in a single physical state

Solute: the substance dissolved in the solution Solvent: the substance the solute is dissolved in

General Properties of Solutions

1. solute particles in solutions are very small

2. solute particles are evenly distributed throughout the solution

3. particles in a solution will not separate under normal conditions

Types of Solutions Aqueous solutions: solutions with water as

the solvent. Electrolyte solutions: aqueous solutions of

ionic compounds. Ionic compounds dissociate allowing for the solution to conduct an electrical charge

Nonelectrolyte solutions: aqueous solutions of molecular compounds. The solute does not dissociate.

Solution Formation When ionic compounds dissolve in water,

they dissociate

NaCl --> Na+ + Cl-

Each component has an attraction to a certain part of the water molecules

Solubility Rules

Used to predict the solubility of ionic compounds. Not all ionic compounds are soluble in water. Some only dissolve partially and some not at all.

Solubility Rules

PRECIPITATION REACTIONS

Precipitation Reactions

Generally reactants are soluble ionic compounds dissolved in water.

When mixed, one of the possible cations joins with one of the anions to produce a compound that is insoluble. The insoluble compound falls out of solution as a

precipitate.

A solution of silver nitrate is reacted with a solution of potassium chloride. Write the complete balanced chemical equation with notations for state of matter.

Write the equation for the reaction of lead (II) nitrate with ammonium sulfide.

Net Ionic Equations

Removes unused ions (spectator ions) from an equation.

Simpler form of a reaction

Examples: write net ionic equations for previous slide examples.

SOLUTION CONCENTRATION

Molarity (M)

Most common expression of solution concentration

M =Mols of solute

Liters of Solution

What is the molarity of a solution formed by mixing 38 grams of potassium hydroxide in enough water to make 250 mL of solution?

If I have a 2.5 M sulfuric acid solution, how many liters of solution will be needed to obtain 70 grams of sulfuric acid? How many milliliters?

SOLUTION STOICHIOMETRY

37 mL of a 0.45 M silver nitrate solution are reacted with 3 grams of copper. What mass of silver will be produced from the reaction?

18 mL of 1.39M sodium iodide is combined with 83 mL of 0.25 M lead (II) nitrate. Will a reaction occur?

If a reaction occurs, what mass of precipitate should be produced?

What volume of 0.750 M Pb(NO3)2, in milliliters, is required to react completely with 1 L of 2.25 M NaCl?

Changing the Concentration of a Solution (Diluting)

M1V1 = M2V2

What volume of 18 M sulfuric acid is needed to create 6 Liters of 3.25 M sulfuric acid?

Describe how you would prepare 400 mL of a 3.75 M solution of nitric acid if given a supply of 14.3 M nitric acid.

Describe how to prepare 500 mL of a 0.8 M solution of sodium hydroxide when provided with solid sodium hydroxide and distilled water.

Saturation

Saturated: solution contains all possible solute under current conditions

Unsaturated: more solute can be dissolved Supersaturated: solution contains solute

past the saturation point for the current conditions