1. Bellringer: 12/16/2016 What is a homogeneous solution?
What is a polar molecule?
STOTD

2. Bellringer: 1/3/ See if you can determine what the following magnified photos are. Number your paper to 5. 1 2 3 4 5

3. The Answers:

4. Partner Review What is a homogeneous mixture? What is a solution?
Provide 2 examples of homogeneous mixtures.

5. Solutions, Acids, and Bases
Chapter 8

6. Solutions Solution Homogeneous Mixture
1 substance dissolves in another
Can be in any state of matter (solid, liquid, gas)
2 parts:
Solute
The substance that is dissolved
Solvent
The substance that does the dissolving
end

7. oxygen & carbon dioxide
Solutions
Example
Solute
Solvent
Air
oxygen & carbon dioxide
(Gas)
nitrogen
Soda
carbon dioxide
Water
(Liquid)
Vinegar
acetic acid
Stainless Steel
chromium and nickel
(Solid)
iron
end

8. - + + Solutions Polar Molecule
Valence electrons are NOT shared equally
1 side is negative
1 side is positive
Water (H2O) -
The Oxygen holds the electrons more
Hydrogen gets the electrons less + +
end

9. Solutions Nonpolar Molecule Valence electrons ARE shared equally
No charge
Carbon dioxide (CO2)
Valence electrons are pulled toward each side
Spreading out the charge.
Tug-of-War
end

10. Solutions Polar Molecules DO NOT dissolve Nonpolar Molecules
ex) Oil and Water don’t mix!
Remember the phrase:
“Like Dissolves Like”
Polar dissolves polar
Nonpolar dissolves nonpolar
end

11. Solutions How is something Dissolved?
When you put a solute into a solvent:
The solvent surrounds the solute
The solvent separates solute 1 molecule at a time
In Ionic Compounds: solvent separates the cations from the anions
Covalent Molecules: solvent breaks molecules into smaller pieces
end

12. Solubility Solubility
The maximum amount of a solute that dissolves in a certain amount of a solvent
Usually written as:
At 50 °C, the solubility of KNO3 is 80 g.
You can dissolve up to 80 g of KNO3 in 100 g of water
end

13. Solubility Solubility Curve What is the solubility of NH3 at 10 °C?
Graph of a compound’s solubility at different temps.
What is the solubility of NH3 at 10 °C?
~ 69 g of NH3 / 100 g of H2O
60 g of NH4Cl can be dissolved in 100 g of water at what temperature?
~ 70 °C
end

14. Solubility
Depending on the amount of solute dissolved, solutions are classified as:
Unsaturated
Saturated
Supersaturated
end

15. Solubility Unsaturated Solutions
Has less than the maximum amount of solute dissolved
Can still dissolve more solute
You have dissolved 60 g of KNO3 in 100g of water
Found BELOW the line on the solubility curve
Unsaturated Solution of KNO3
end

16. Solubility Saturated Solution
Has the maximum amount of solute dissolved
Cannot dissolve anything else
You have dissolved 80 g of KNO3 in 100g of water
Found ON the line of the solubility curve
Saturated Solution of KNO3
end

17. Solubility Supersaturated Solution
Supersaturated Solution of KNO3
Supersaturated Solution
Has more than the maximum amount dissolved
You have dissolved 130 g of KNO3 in 100 g of H2O
Found ABOVE the line on the solubility curve
end

18. Bellringer: 1/4/2017
Use the solubility curve in your packet to answer the following questions:
What temperature will dissolve 60 grams of NH3?
I made a solution using 60 grams of sodium nitrate at 30 ⁰C. Did I make a saturated, unsaturated, or supersaturated solution?
STOTD

19. Schedule and Updates
1/4/17 (Wed): Properties of solutions, Acids & Bases
1/5/17 (Thurs): Review & LAB!!!
1/6/17 (Fri): Review, Quiz, Packet due
~Weekend~
1/9/17 (Mon): Light
1/10/17 (Tues): Electricity
1/11/17 (Wed): Mini Lab
1/12/17 (Thurs): Magnetism w/ Mini lab
1/13/17: Review, Quest, Packet due
1/16/17: No School (MLK day)
1/17-20/17: Review for Final Exam

20. Solubility To create a supersaturated solution:
Dissolve as much solute as possible
Heat the solution and dissolve more solute
Allow the solution to cool slowly
Supersaturated Solutions are very sensitive
Shaking/stirring or adding more solute, will make the extra solute fall out of solution
end

21. Properties of Solutions
Conductivity
Ionic Compounds(aq) and Acids(aq) conduct electricity
Electrolytes
Covalent Molecules will NEVER conduct electricity
Nonelectrolytes
Pure water WILL NOT conduct electricity
end

22. Pure Water- No flow of electricity Pure NaCl- No flow of electricity
Water + NaCl- Electricity
end

23. Properties of Solutions
Electrolytes
Conduct when dissolved
Strong Electrolyte
Good Conductor
Completely Dissolves into IONS
Weak Electrolyte
Poor Conductor
Small Amount Dissolves into IONS
Nonelectrolyte
Does NOT Dissolve into IONS
end

24. Properties of Solutions
Freezing Point
Dissolving a substance lowers the freezing point
Salt put on icy roads
Boiling Point
Dissolving a substance raises the boiling point
Radiators have ethylene glycol dissolved in water
end

25. Rates of Dissolving 4 ways to make something dissolve faster:
1. Increase concentration of solvent
Add more solvent
2. Increase the surface area
Grind it up
3. Stir the solution
4. Increase the temperature
end

26. Acids and Bases
Acid
A compound that produces the hydronium ion (H3O+) when dissolved in water
H2O + HCl  H3O+ + Cl-
Chemical formulas start with an “H”
HCl, H2SO4, H3PO4
Remember: H+ = H3O+
end

27. Acids and Bases 3 general properties of acids: 1. Sour Taste
Like vinegar or spoiled milk
2. Reactive with Metals
Mixed with metals they will produce hydrogen gas
3. Color change in indicators
0-6 on pH scale
Phenolphthalein turns colorless
Litmus paper turns red
end

28. Acids and Bases Base A compound that produces the hydroxide ion (OH-)
NaOH  Na+ + OH-
Chemical formulas end with an “OH”
NaOH, Mg(OH)2, Al(OH)3
end

29. Acids and Bases 3 general properties of bases: 1. Bitter Taste
Like dark chocolate and Cough syrups
2. Slippery Feeling
The base is dissolving your skin cells
3. Color change in indicators
8-14 on the pH scale
Phenolphthalein turns pink/red
Litmus paper turns blue
end

30. Chemical Reaction Neutralization Reaction between an acid and a base
This is a Double-Replacement Reaction
Produces a salt and water
HCl + NaOH  H2O + NaCl
H2SO4 + Mg(OH)2  2H2O + MgSO4
Acid
Base
Water
Salt- an Ionic Compound
end

31. Strength of Acids and Bases
pH scale
A measure of the hydronium ion (H3O+) concentration
More H3O+ = More Acidic = Lower pH
Neutral
Acidic
Basic
end

32. Strength of Acids and Bases
Acids/Bases are classified as strong or weak
How much they break down to form H+ and OH- ions
When you mix a weak acid/base with the salt from the neutralization reaction:
You Form a Buffer
A solution that keeps the same pH value when an acid/base is added to the solution
end