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