+

Solubility Notes

Chemistry 5/5/14

+DrillUse the table from pg. 10 to give the

amount of substances that will dissolve in 100 g of H2O: NH3 at 10°C and 80°C

Why does solubility of NH3 decrease at higher temperatures?

KCl at 10°C and 70°C If 50 g of KCl were dissolved in 100 g of

water, and it was cooled to 50°C, what kind of solution would you have?

HW: Back of pg. 5 (Cross out “Henry’s Law” and #9)

+Objectives

IWBAT List factors that increase rate of solution. List factors that increase degree of solubility. Explain dissolution of a solid in a liquid. Define suspension, colloid, and emulsion.

+

Substances with similar bonds dissolve into each other. Polar & Polar

Water and Isopropanol (Rubbing Alcohol) Polar & Ionic

Water and most Salts (NaCl, CaCl2, KI, etc.) Nonpolar & Nonpolar

Nail Polish and Nail Polish Remover Oil Paint and Terpentine

Why doesn’t oil dissolve in H2O?

Oils are non-polar molecules.

Water is a polar molecule.

Molecules with unlike bonds do not dissolve into each other.

Oil - No charge on the molecule

Water -Separation of

Charge

+

Animation of Salt Dissolving

Describe NaCl dissolving in H2O

Water is a dipole.

NaCl dissociates into Na+ ions and Cl- ions.

The - end of the H2O molecule is attracted to the Na+ ion in the salt crystal and pulls it into the water.

The + end of the water is attracted to the Cl- ion.

http://nobel.scas.bcit.ca/chem0010/unit9/9.4_solubilityionic.htm

http://nobel.scas.bcit.ca/chem0010/unit9/9.4_solubilityionic.htm

+YOU ANSWER

What are the different ways to buy juice?

If you watered down a drink, what would you be doing?

+ Dilution and Solutions

Dilute vs. Concentrated: Dilute – small amount of solute, large amount of

solvent Concentrated – small amount of solvent, large

amount of solute

Molarity -- the measurement of the number of moles of solute per liter of solvent M = n / V M -- molarity n -- number of moles V -- total volume of solution

+Mixtures that are like Solutions, but aren’t Solutions!

Suspension Mixture where particles eventually settle

to the bottom Particles are MUCH bigger than a solution.

They may be visible ex. Chocolate is suspended in hot

chocolate or chocolate milk ex. Tiny particles of dirt (silt) are

suspended in river or pond water

+Like Solutions, but not, cont.

Colloid Mixture containing particles of a size between

suspension and true solution The particles are not actually dissolved, but

also not as large as a suspension’s particles. Particles remain dispersed (do not settle out),

but not dissolved: may appear cloudy: ex. fog, aerosols,

smoke, plain milk may appear as something between two

phases: ex. Jell-o

Suspension, Colloid, Solution (L to R)

Notice that the particles have settled out of the Suspension

A Colloid’s particles reflect light

A Solution’s particles DON’T reflect light - looks clear!

http://dl.clackamas.cc.or.us/ch105-03/similar.htm

+Like Solutions, but not, cont.

Emulsions Colloidal dispersions of liquid in liquid Tiny particles of one liquid dispersed in

another liquid, but NOT dissolved. These are held together by an emulsifier:

An emulsifier causes two immiscible liquids to mix because one end is polar and one is nonpolar.

ex. egg in mayonnaise, soap in soapy water

Soap Molecule

Soap molecules immersed in grease stain

Nonpolar molecule of grease

+

The End!

How many solutions do you think you encounter on a daily basis?