Chapters 15 (solutions) and 19 (acids and bases) Solutions Notes Chapters 15 (solutions) and 19 (acids and bases)

Components of a Solution Solute: Solvent:

II. Types of Solutions Based on the state of matter of the solvent Any combination of gas, liquid or solid! Give examples of 3 different types of solutions:

Mothballs – naphthalene (flammable) or 1,4-dichlorobenzene Brass – copper and zinc Hydrogen in platinum – hydrogen fuel cells

III. Factors Affecting the Rate of Solution Aqueous Gas: Stirring No stirring or shaking Heat Cold temperatures Small particle size (increases surface area) Increased pressure Coca-cola

IV. Solubility Saturated - has all solute that can be dissolved at a given temperature Unsaturated - can dissolve more solute at that given temperature Supersaturated - has more solute dissolved than it should at that temperature Unstable, crystals will form Rock candy is an example Supersaturated solution Supersat 2 Sat vs. unsat

IV. Solubility d. What does a solubility curve show? -show dependence of solubility on temperature -solids - increase in solubility as temp increases -gases - decrease in solubility as temp increases All points “on the line” represent the grams of solute required to form a saturated solution at the given temperature

IV. Solubility - Solubility Curve

V. How Solutions Form Solvation is the dissolving process Solvent surrounds solute (based on charges - opposites attract) Pulls solute into solution What dissolves in a … Polar solvent Nonpolar solvent General rule:

VI. Electrolytes vs. Nonelectrolytes Electrolyte - forms ions in solution Conducts electricity Nonelectrolyte - does not form ions in solution (even if it dissolves) Does not conduct electricity A compound is an electrolyte if Ionic compounds that are soluble in water (must be aqueous, solid ionic compounds are NOT electrolytes) Acids (formula starts with H)

VII. Concentration of Solutions Concentration Formula - based on definition of concentration and molarity Molarity = moles of solute per liter of solution Formula: If given mass of the substance, you must first convert to moles using molar mass from the periodic table Must be liters (L) not milliliters (mL) 1L = 1000mL If given mL, divide by 1000 to get L

VII. Concentration of Solutions b. Examples: i. What is the concentration if 2.5moles of NaCl is dissolved in 750mL of water?

VII. Concentration of Solutions b. Examples: ii.What is the concentration if 15.2g of NaCl is dissolved in 500mL of water?

VII. Concentration of Solutions b.Examples iii.How many liters of a 0.25M solution can be made from 50.0g of CaCl2?

VII. Concentration of Solutions c.Dilution formula - adding water to make a solution more dilute (less concentrated) -have the same number of moles of the solute, but a larger volume of solvent Formula:

VII. Concentration of Solutions c. Dilution examples iv.Calculate molarity if 37.5mL of 12.0M HCl is diluted to 150.0mL

VII. Concentration of Solutions c. Dilution examples v.Calculate molarity if 15.0mL of 6.0M H2SO4 is diluted to 250.0mL?

VII. Concentration of Solutions c. Dilution examples vi.How would you make 500.mL of 1.5M NaCl from a 5.0M stock solution?