1. Solubility Curve Day 2

2. Solubility
Solubility- maximum amount of substance that can be dissolved in a given amount of solvent
Solubility depends on temperature, pressure, and type of solvent being dissolved
Solubility is not affected by agitation and surface area.

3. SolubLE By soluble we mean capable of being dissolved.
Suppose a sugar cube is dropped into a glass of water. You know from experience that the sugar will dissolve. Sugar is described as “soluble in water”
By soluble we mean capable of being dissolved.
All traces of the sugar are gone but we know it is there because the water tastes sweet throughout. This mixture is now a solution.
Solvent: The dissolving medium in a solution; what dissolves another substance.
Solute: The substance being dissolved in a solution.

4. Solute and Solvent
Solute Solvent Aqueous Solution

5. Solubility
A saturated solution contains the maximum quantity of solute that dissolves at that temperature.
A unsaturated solution contains less than the maximum amount of solute that will dissolve in a given amount of solvent.

6. Saturated & Unsaturated

7. supersaturated
A supersaturated solution contains more than the maximum amount of solute that can dissolve at a particular temperature. (Not all solute is dissolved)

8. saturated Solution

9. Factors that affect solubility

10. Solutions Example Solute Solvent Solid Liquid Gas
Brass (Zinc & Copper)
Sugar in water
Alcohol in water
Fog (water in air)
Soda (Carbon dioxide in syrup)
Air (Oxygen in Nitrogen)

11. SOLUBILITY OF SOLIDS “LIKE DISSOLVES LIKE”

12. Effect of Heated solvent on dissolved gases
INCREASING TEMPERATURE
When a solution is heated, the dissolved gases held within are let off and decrease.
The kinetic energy increases causing the molecules of the solvent to move more rapidly.
As the molecules move they provide space for the dissolved gases to move.
The gas is less dense than the liquid so it will rise to the surface and be let off.

13. Temperature
A warm liquid will dissolve more solute-solid than a cold liquid.
An increase in temperature will result in an increase in solubility of a solid in a liquid.
This is not the case for everything.
Have you ever observed bubbles forming before the water reaches boiling point.
These bubbles are dissolved atmospheric gases escaping from the water.

14. Temperature & Dissolved Oxygen
Oxygen and Nitrogen become less soluble in water as the temperature increases.
When an industrial plant take COOL water from a lake and then dumps HOT water back in the lake, the temperature of the entire lake increases.
Such a change in temperature is known as THERMAL POLLUTION
The increase in temperature lowers the dissolved oxygen in the lake.
The lower amounts of dissolved oxygen can harm the aquatic animals and plants in the lake.

15. EFFECT OF HEATED SOLVENT ON DISSOLVED GASES (Continued)
DECREASING TEMPERATURE
When solvents cool they can hold more gas.
As the temperature decreases the kinetic energy decreases.
As the kinetic energy decreases the molecules move closer together and move less.
Gases get trapped between the molecules of the cooling solvent keeping it in solution.

16. Pressure & solubility
If there is an increase in the pressure of a gas there is also an increase in the solubility of the gas.
Ex: Carbonated beverages- Once you pop the top on a Coke, The external pressure has been reduced, and the solubility of CO2 goes down. This is why Coke goes flat once you open it.
Pressure does NOT have any significant effect on the solubility of liquids or solids in water (solvent).

17. Types of Mixtures
Mixtures are classified by how thoroughly the substances mix
Heterogeneous and Homogeneous Mixtures
Solutions, Suspensions, Colloids

18. Matter Flowchart MATTER MIXTURE PURE SUBSTANCE yes no
Can it be physically separated?
Homogeneous Mixture
(solution)
Heterogeneous Mixture
Compound
MIXTURE
PURE SUBSTANCE
yes no
Can it be chemically decomposed?
Is the composition uniform?
Element

19. Mixtures
Mixture: A physical change resulting in 2 or more substances mixed together
Mixtures can be separated by Physical Means.
Each substance keeps its own identity.

20. Heterogeneous vs. Homogeneous Mixtures
Characteristics of Heterogeneous Mixtures
Not same throughout
Uneven distribution
Particles are large enough to see, and can be separated from mixture easily.
Characteristics of a Homogeneous Mixture
Same throughout
Even distribution
Solution
Particles are very small and not easily seen or separated

21. Solutions vs. Suspensions
Solution- a homogeneous mixture of two or more substances in a single physical phase.
Examples: salt and water, sugar and water, copper(II) chloride and water
Suspension- heterogeneous mixture containing solid particles that are sufficiently large for sedimentation
Suspensions are "murky" or "opaque". They do not transmit light. The mixture of particles can be separated by filtration.
Example: sand and water

22. Mixtures Colloid – is a type of mixture that never settles
Its particles are larger than in a solution but not heavy enough to settle
Milk and gelatin are examples of colloids
Milk is a mixture of water, fats, and proteins in varying proportions and its components will never settle if left standing
Tyndall Effect – the scattering of lght by colloidal particles
Solutions don’t scatter light because their particles are to small
Think of what fog does to light  fog is a colloid
The light beam is not visible as it passes through a true solution (left), but it is readily visible as it passes through colloidal iron (III) oxide in water

23. Consider this Phase Diagram
What process is occurring when a substance changes from point X (180 °K and 0.03 atm) to point Y (160 °K and .065 atm)?
A) Melting (Fusion)
B) Evaporation
C) Deposition
D) Condensation Y X

24. Which of the following processes is exothermic?
A) A gas changes to a liquid
B) A solid changes to a liquid
C) A liquid changes to a gas
D) A solid changes to a gas

25. Which of the following particles is an electrolyte?
A) SO2
B) Al2(SO4)3
C) N2H4
D) CH4

26. The forces that keep atoms in a molecule together are called?
A) Strong Covalent Bonds
B) Weak Intermolecular Forces
C) Weak Ionic Bonds
D) Strong Intramolecular Forces

27. Between points X and Y, which of the following would be observed?
A) Liquid and vapor will be present
B) Solid and liquid will be present
C) Only liquid will be present
D) Only solid will be present X Y

28. Consider this Phase Diagram
At what temperature does the normal boiling point occur?
A) °K
B) °K
C) °K
D) °K