The Dissolving Process

1
Chapter 20

• The Dissolving Process
• Part 1

2
Solutions

• Solutions are homogeneous mixtures.

3
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.

4
Water

• The universal solvent.

5
Air

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

6
What is the solvent in air?

• The solvent is the major component in a solution.
• All lesser components are solutes.

7
Miscibility

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

8
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.

9
Dissociation is a process in which ionic
compounds separate or split into ions.
10
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.

11
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.
12
Red Blood Cells
13
Crescent or sickle-shaped red blood cells (RBCs)
are present with Sickle cell anemia, and stand
out clearly against the normal round RBCs.
14
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?

15
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.

16
Woods Metal

• Wood's metal is a an alloy with a melting point
  of approximately 70C (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.

17
Homework

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