1. The Dissolving Process Part 1
Chapter 20
The Dissolving Process
Part 1

2. Wood’s Metal Demo
Wood's metal is a an alloy with a melting point of approximately 70°C (158 °F). It is 50% bismuth, 26.7% lead, 13.3% tin, and 10% cadmium by weight.
Wood's metal is useful as a fire-melted valve element in fire sprinkler systems in buildings. Medical gas cylinders in the United Kingdom have a Wood's metal seal which melts in fire, allowing the gas to escape and reducing the risk of gas explosion.

3. Solutions
Solutions are homogeneous mixtures.

4. Solutes and Solvents “solute” is what is being dissolved.
“solvent” is what it is dissolved in.
If we make tea and mix sugar into it. The sugar and tea are the solutes. Water is the solvent. The sweet tea is the solution.

5. Water
The universal solvent.

6. Air
Air is a homogeneous mixture of gases.
Air is a solution of gases.

7. What is the solvent in air?
The solvent is the major component in a solution.
All lesser components are solutes.

8. Miscibility
Liquids that are soluble in each other in all proportions are miscible.
Liquids can also be partially miscible or immiscible.

9. Solvation
Solvation is the process of solvent particles attaching with particles of a solute. As solute dissolves in a solvent the solute particles spread out and become surrounded by solvent particles.
If water is the solvent we call this process hydration.

10. Dissociation is a process in which ionic compounds separate or split into ions.

11. Like Dissolves Like
like dissolves like" is an expression used by chemists to remember how some solvents work.
It refers to "polar" and "nonpolar" solvents and solutes.

12. Water – Cooking Oil – Food Coloring.
Water is Polar.
What are the polarities of cooking oil and food coloring?
Cooking Oil is nonpolar. Food Coloring is polar.

13. Red Blood Cells

14. Crescent or sickle-shaped red blood cells (RBCs) are present with Sickle cell anemia, and stand out clearly against the normal round RBCs.

15. Some solute-solvent combinations are: (solute state-solvent state)
oxygen in nitrogen (gas-gas) = air
carbon dioxide in water (gas-liquid) = soda pop
water vapor in air (liquid-gas) = humidity
alcohol in water (liquid-liquid) = liquor
mercury in silver (liquid-solid) = dental amalgam
sugar in water (solid-liquid) = kool-aid
tin in copper (solid-solid) = bronze alloy
How many other combinations are possible?

16. Other solute – solvent combinations
(solid-gas) = Mothballs sublime in air
(gas-solid) = Hydrogen dissolves rather well in metals; an example is hydrogen in palladium which is used as a gas stove lighter.

17. Homework Worksheet: The Dissolving Process
You should be able to complete the front of this worksheet.