Agenda: Warm-up: Explain the solvation process

Review – terms, importance, “likes dissolve likes”

Solubility Curves What can they tell us about solutions?

Measuring concentration of solutions

Homework: New Element Project

Warm-up: Solvation ProcessExplain what is happening when an ionic

compound is dissolved in water (called solvation or hydration)

View the video - what are key steps that need?How does the water molecules interact with

the ionic compound?

http://group.chem.iastate.edu/Greenbowe/sections/projectfolder/flashfiles/thermochem/solutionSalt.html

a. Making Solutions: Molecules (Covalent compounds)

General Rule: “Likes dissolve likes”

Polar solutes can dissolve in polar solvents.Examples:

Organic solventsNon-polar solute can dissolve in non-polar solvents

Examples: To remove oily stains in dry-cleaning

Lipids will dissolve in hydrocarbonTo clean oil based paintsTo manufacture plastics, man-made

fibers, adhesives

Solution process

Solution processAnimations https://

www.youtube.com/watch?v=EBfGcTAJF4o

b. Making Solutions: Factors that impact the solubility of solids in liquids

Energy is involved – 2 stepsEndothermic to separate solute & solvent particlesExothermics – attraction between solvent & solute

particlesFactors affecting solids dissolving in liquids

General trend to increase solubility

Chemical components of solute and solvent

Intermolecular forces High attraction between solute and solvent particles

Temperature

Particle size

Agitation (amount of stirring)

c. Measuring ConcentrationSolubility: number of grams of solute in 100

grams of water at 20℃ Solubility Curves

Saturated solutionsUnsaturatedSupersaturated

http://www.youtube.com/watch?v=XSGvy2FPfCw http://www.youtube.com/watch?

v=1y3bKIOkcmk&feature=related

Interpreting solubility curvesY axis

X axis

Lines

If the amount needed is more or less than 100 g of H₂O

1 g H₂0 = 1 mL H₂0

c. Making solutions: Factors that affect the solubility of gases in liquids

Factors affecting gases

General trends to increase solubility

Temperature

Pressure

Think about soda (carbonated drinks)

Category Ions Except with these ions

Examples

Soluble cations

Group 1 ions and ammonium, NH4

+No exceptions

Na2CO3, LiOH, and (NH4)2S are soluble.

Soluble anions

NO3- and

C2H3O2- No exceptions

Bi(NO3)3, and Co(C2H3O2)2 are soluble.

Usually soluble anions

Cl-, Br-, and I-

 

Soluble:Exceptions: Ag+ and Pb2+

CuCl2 is water soluble, but AgCl is insoluble.

  SO42-

Soluble Exceptions:Ba2+ and Pb2+

FeSO4 is water soluble, but BaSO4 is insoluble.

Usually insoluble anions

CO32-, PO4

3-, and OH-

Insoluble: Exceptions: group 1 elements and NH4

+

CaCO3, Ca3(PO4)2, and Mn(OH)2 are insoluble in water, but (NH4)2CO3, Li3PO4, and CsOH are soluble.

Solubility Rules determined under specified concentration (often 0.1% molarity)

d. Measuring Concentrations Molarity (M) by definition =

Molarity = Moles of solute 1 Liter of solution

Therefore: 2 molar solution = __________________

Discovery Education video Standard Deviants School Chemistry: solutions &

dilutions

Molarity: moles of solute liters of solution

Molarity problems M= moles_______ 1 Liter solutionWhat I s the molarity of a solution in which

58 gram of NaCl are dissolved in 1.0 L of solution?

What is the molarity of a solution in which 10.0 grams of silver I nitrate is dissolved in 500 mL of solution?

How many grams of potassium nitrate should be used to prepare a 2.0 L of a 0.5 molar solution?

Steps needed in molarity calculationsMoles

For grams:

Liters of solutionIf less than 1L ? mL = 1L

Comparison __________ = moles of solute1 liter of solution

Molarity practiceTo what volume should 5.0 g of KCl be diluted

in order to prepare a 0.25M solution?

How many grams of copper II sulfate – penta hydrate are needed to prepare 100 mL of a 0.10M solution?

9g. Dilution of concentrated solutions: V₁M₁= V₂M₂Molarity by dilution practice problems

Most reagents are sold & sorted in concentrated solutions

How much concentrated 18M sulfuric acid is needed to prepare 250mL of a 6.0M solution?

How much concentrated 12M hydrochloric acid is needed to prepare 100 mL of a 2.0 M solution?

To what volume should 25 mL of 15 M nitric actid be diluted to prepare a 3.0 M solution?

To how much water should 50 mL of 12 M hydrochloric acid be added to produce a 4.0 M solution?

To how much water should 100 mL of 18M sulfuric acid be added to prepare 1.5 M solution?

Colligative PropertiesThe properties of the solution that depend on the

number of particles in solution, not the identity of the solute. The solvent properties will be changed.

NaClCaCl₂AlCl₃

Melting point depression; boiling point elevation; Vapor pressure lowering

Resourceshttp://

www.karentimberlake.com/solution.htm

http://www.afn.org/~afn02809/powerpoint-list.htm

http://www.chemistrygeek.com/chemistrypowerpoint/Student%20Ch%2015%20Solutions.ppt

http://college.cengage.com/chemistry/general/zumdahl/world_of_chem/1e/instructors/ppt/figures/viewindex.html

Solution process