Physical Properties of Solutions

Chapter 12

SolutionStoichiometry

end of Chapter 4

TitrationsIn a titration a solution of accurately ________is added gradually added to another solution of _______concentration until the chemical reaction between the two solutions is complete.

__________________– the point at which the reaction is complete

_________– substance that changes ______ at (or near) the equivalence point

Slowly add _____to unknown ____

UNTIL

the indicatorchanges color

4.7

What volume of a 1.420 M NaOH solution isRequired to titrate 25.00 mL of a 4.50 M H2SO4 solution?

4.7

x1

x1

x =

M

acid

rx

coef.

M

base

Boiling-Point Elevation

0

0

Tb = Kb m

12.6

Freezing-Point Depression

0

0

0

Tf = Kf m

12.6

12.6

What is the freezing point of a solution containing 478 g of ethylene glycol (antifreeze) in 3202 g of water? The molar mass of ethylene glycol is 62.01 g.

m =

12.6

Colligative Properties of Electrolyte Solutions

12.7

_______NaCl solution ____ ions in solution

nonelectrolytesNaCl

CaCl2

i should be

____

__

Which would you use for the streets of Bloomington to lower the freezing point of ice and why? Would the temperature make any difference in your decision?

a) sand, SiO2

b) Rock salt, NaCl

c) Ice Melt, CaCl2

Change in Freezing Change in Freezing Point Point

Boiling-Point Elevation Tb = i Kb m

Freezing-Point Depression Tf = i Kf m

Colligative Properties of Electrolyte Solutions

12.7

Change in Freezing Change in Freezing Point Point

Common Applications of Common Applications of Freezing Point Freezing Point DepressionDepression

Propylene glycol

Ethylene glycol – deadly to small animals

At what temperature will a 5.4 molal At what temperature will a 5.4 molal solution of NaCl freeze?solution of NaCl freeze?

Freezing Point Freezing Point DepressionDepression

A colloid is a _______of particles of one substance throughout a dispersing medium of another substance.

Colloid versus solution

• collodial particles are much _____than solute molecules

• collodial suspension is not as ________as a solution

12.8

Colloids

• Brownian motion • Tyndall Effect

Suspensions

• These are mixed, but not dissolved in each other

• Will settle over time

• Particles are bigger than 1 micrometer (larger than colloid)

• Examples: dust in air, muddy water