Types of mixture- Homogeneous and heterogeneous

2.  Solution – a homogeneous mixture of
two or more substances
solute – substance being dissolved
solvent – dissolving medium
For a salt water solution:
The solute is
salt
The solvent is
water

3.  SOLUBILITY
The amount of a substance which will dissolve in a given
amount of a particular solvent under certain conditions (ie.
temperature and pressure.
Which substance has the
highest solubility at 20oC?
KI
How many grams of KCl
will dissolve in 200 g of
water at 60oC?
90 g

4. For all solutions:
soluble – will dissolve
insoluble – will not dissolve
For liquid/liquid solutions only:
Miscible - will dissolve Immiscible – will not dissolve

5.  Unsaturated Solution – when less solute is
dissolved in a solvent than is possible under the
existing conditions
 Saturated Solution – when as much solute is
dissolved as possible under the existing conditions
 Supersaturated Solution – when more solute is
dissolved in a solvent than should be possible under the
existing conditions

6.  An unsaturated solution?
It would dissolve
 A saturated solution?
It would sink to the bottom
(it would not dissolve)
 A supersaturated solution?
Crystals of solute will start precipitating

7. Heating
Stirring
Increasing Surface Area

8.  For Solids:
In general, the solubility of a solid in a liquid
increases as the temperature of the solvent
increases.

9.  For Gases:
1. In general, the solubility of a gas in a liquid
decreases as the temperature of the liquid
solvent increases.
2. Henry’s Law:
The solubility of a gas
in a liquid is directly
proportional to the
pressure of the gas over
over the liquid.

10.  A heterogeneous mixture whose particles
(which are relatively large) will settle out
upon standing

11.  A homogeneous / heterogeneous
(depending on the source!) mixture whose
particles, which are intermediate in size, will
not settle out upon standing

12. CHARACTERISTICS OF
SOLUTIONS, SUSPENSIONS, AND COLLOIDS
PROPERTY SOLUTIONS COLLOIDS SUSPENSIONS
Particle Size
Small
(0.1 – 1 nm)
Medium
(1-100 nm)
Large
(100 nm or larger)
Tyndall Effect No Yes No
Effect of Gravity Do not settle out Do not settle out Settle out
Filtration
Cannot be
separated
Cannot be
separated
Can be separated
Uniformity Homogeneous Borderline Heterogeneous

13.  The visible path produced by a beam of light
passing through a colloidal mixture; caused
by the scattering of light by the dispersed
particles

14. EXAMPLES OF SOLUTIONS AND COLLOIDS
TYPE SOLUTION COLLOID
Solid/Solid Alloys (brass, etc.) Colored gems
Solid/Liquid Ocean water
Jell-o, jelly, blood
(gels and sols)
Solid/Gas Sulfur vapor in air Smoke
Liquid/Solid Mercury in copper Pearls, Opals
Liquid/Liquid Alcohol in water Mayonnaise (emulsions)
Liquid/Gas Fog Hair spray (aerosols)
Gas/Solid
Hydrogen adhered to
platinum
Ivory soap, marshmallows
Gas/Liquid Dr. Pepper, Sprite Whipped cream (foams)

15.  Gels and Sols
colloidal mixtures of a solid dispersed in a liquid
 Emulsions
colloidal mixture of a liquid dispersed in a liquid
 Aerosols
colloidal mixture of a liquid dispersed in a gas
 Foam
colloidal mixture of a gas dispersed in a liquid