SCH3U- DAY 11

CHAPTER 8- Solutions and Their Properties

LEARNING GOALS

SUCCESS CRITERIA

- I will learn how to classify solutions

- I will learn about factors that affect solubility

- I will learn about solution concentrations

- I will learn about preparing solutions in a lab

- I will be able to explain the difference between saturated,

unsaturated and supersaturated

- I will be able to predict whether conditions will increase or

decrease solubility

- I can handle the calculation questions! Mwahah

8.1: CLASSIFYING SOLUTIONS

WHAT IS A SOLUTION?

• Homogenous mixture of two or

more substances

• Evenly mixed: same proportions

throughout

SOLUTE AND SOLVENT

• Solvent: present in greatest amount

in the solution

• Solute: Any other substance in the

solution

• Aqueous solutions: Solutions with

water

• Not all solutions are aqueous!

9 DIFFERENT TYPES!

• Page 355!

• E.g. steel, ice, natural gas

SOLUBILITY

• Maximum amount of solute that will dissolve in g

solvent at a specific temperature

• Usually in g/100 mL water at 20*C

• E.g. NaCl is 35.9 g/100 mL of water at 20*C

• O2 is 0.0009 g/100mL water at 20*C

Why the temperature?

SATURATED, UNSATURATED

• Unsaturated: you CAN

dissolve more solute

• Saturated: you CAN’T dissolve

more solute

Not full! Full!

SUPERSATURATED

• More solute than a saturated solution at the

same temperature

• We force it to accept more

• VERY UNSTABLE

• Touch it, add crystal: excess will PRECIPITATE

OUT

8.2: FACTORS THAT AFFECT SOLUBILITY AND RATE OF DISSOLVING

HOW DOES SOMETHING DISSOLVE?

• Three forces:

• Solute + solute

• Solvent + solvent

• Solute + solvent

• In a solution, solute is attracted to solvent

• Solute intermolecular forces BROKEN

• Some solvent intermolecular forces broken

GASES

• React more easily

• Less attractive forces!

AQUEOUS SOLUTIONS

• Water is highly polar

• Recall: hydrogen bonding

• When H is bonded to O, F, N

(very electronegative elements)

IONIC COMPOUNDS IN WATER

• Most ionic compounds are soluble in water

• Water can pull ions apart from each other

• Hydration: water molecules surround each ion

• The compound dissolves!

• If solute-solute attraction too high -> WON’T DISSOLVE

• If ionic compound is (aq) -> means have separated and

distributed evenly throughout solution

MOLECULAR COMPOUNDS IN WATER

• Polar molecules will dissolve

• Non-polar molecules do not dissolve (can’t break hydrogen

bonds)

• Recall: ionic compounds in solution conduct electricity

• Molecular compounds usually do not

WILL AN IONIC COMPOUND DISSOLVE?

• Two factors: charges on the ions

and SIZE

• The greater the charge on the ions

-> LESS SOLUBLE

• Smaller the size -> LESS SOLUBLE

• Think: if very large ions in the

compound, weak attraction

WILL A MOLECULAR COMPOUND DISSOLVE?

• Smaller the size of the non-polar section -> more

soluble in water

LIKE DISSOLVES LIKE

• Polar dissolves polar

• Non-polar dissolves non-polar

• Works for gases in water too!

• If has both polar/non-polar

part, can dissolve in both (e.g.

detergent)

TEMPERATURE AND SOLUBILITY

• Higher temperature -> solubility

increases for solid solute in

liquid

• More collisions with the solute

• Why you need to specify

temperature

• Liquid solute: not affected by

temperature

• Gas in gas: not affected by

temperature

• Gas in solid: affected by temperature

+ pressure hotter it is, less soluble

• Thermal heat pollution!

PRESSURE AND SOLUBILITY

• Pressure: force per unit area

• Affects gas solubility

• Solubility of gas in liquid is directly proportional to

THAT gas above the liquid

• Scuba diving

FACTORS THAT AFFECT RATE OF DISSOLVING

• How quickly solute dissolves in the solvent

• NOT the amount, just how fast it dissolves

• 1) MIXING

• 2) TEMPERATURE

• 3) SURFACE AREA

LAB #2:

• http://www.glencoe.com/sites/common_assets/science/virtual_labs/PS15/PS15.html

IMAGE SOURCES

• http://www.athenaes.com/images/ShirtDesign.gif

• http://k12opened.com/ebooks/sci/ebook-mixtures-solutions/img/solution.jpg

• http://chem270.wikispaces.com/file/view/35933750.jpg/303175616/35933750.jpg

• https://tse1.mm.bing.net/th?id=OIP.IMULmVxBN1Wyy3rynjwl5gEsDG&w=263&h=170&c=7&qlt=90&o=4&pid=1.7

• http://www.utdallas.edu/~brikowi/Teaching/Field_Methods/naCl_inWater.png

• https://d2gne97vdumgn3.cloudfront.net/api/file/GwMLx1F6TdyDBE35Sz3f

• http://www.eppm.com/downloads/449/download/shutterstock_129205010.jpg?cb=5d37bc3fe2dac5a3d5e81c677234ac7a

• http://galedc.com/uploads/c798aead433203cb7c4b07fb1baa31ed2176.JPG

• http://www.biology.iupui.edu/biocourses/N100H/images/waterdissolve.gif

• http://wps.prenhall.com/wps/media/objects/3311/3390507/imag0401/AAAUAVA1.JPG

• http://dwb4.unl.edu/CHEM/CHEM869A/CHEM869AMats/SaltSol_files/SaltSolT.gif

• https://image.slidesharecdn.com/solubility-150522124309-lva1-app6892/95/solubility-physical-pharmacy-32-638.jpg?cb=1432298789

• http://image.tutorvista.com/content/feed/u303/Thermal_Pollution.pdf.jpg

• http://i.ebayimg.com/images/i/281437202865-0-1/s-l1000.jpg

• http://g3yxi3w953w3xjjaj1xcbuay.wpengine.netdna-cdn.com/wp-content/uploads/2015/01/Dollarphotoclub_75628098-e1422257536867.jpg