Unit 5: Solutions, Acids, and Bases

Essential Questions:

1. What are the properties of solutions?
2. What are solute and solvent and what factors affect the rate of dissolving?
3. How is solution concentration expressed in terms of Molarity and molality?
4. How are molar and molal solutions prepared?
5. What are colligative properties and how are they related to molal concentration for non-electrolyte solutes?
6. What are the properties of acids and bases?
7. Compare and contrast Arrhenius and Bronsted-Lowry acid-base theories.
8. Describe the difference between strong and weak acids.
9. Describe the relationship between the pH scale and the presence of hydronium and hydroxide ions in solution for acids and bases.
10. Experimentally neutralize an acid and a base and write a balanced chemical equation to represent this reaction.
11. Describe a titration and the function of a titration.

GSE:

SC6. Obtain, evaluate, and communicate information about the properties that describe solutions and the nature of acids and bases.

a. Develop a model to illustrate the process of dissolving in terms of solvation versus dissociation.

b. Plan and carry out an investigation to evaluate the factors that affect the rate at which a solute dissolves in a specific solvent.

c. Use mathematics and computational thinking to evaluate commercial products in terms of their concentrations (i.e., molarity and percent by mass).

d. Communicate scientific and technical information on how to prepare and properly label solutions of specified molar concentration.

e. Develop and use a model to explain the effects of a solute on boiling point and freezing point.

f. Use mathematics and computational thinking to compare, contrast, and evaluate the nature of acids and bases in terms of percent dissociation, hydronium ion concentration, and pH. (Clarification statement: Understanding of the mathematical relationship between negative logarithm of the hydrogen concentration and pH is not expected in this element. Only a conceptual understanding of pH as related to acid/basic conditions is needed.)

g. Ask questions to evaluate merits and limitations of the Arrhenius and Bronsted-Lowry models of acid and bases.

h. Plan and carry out an investigation to explore acid-base neutralization

Vocabulary:

1. solute
2. solvent
3. solution
4. suspension
5. colloid
6. Tyndall effect
7. soluble
8. miscible
9. immiscible
10. concentration
11. molarity
12. molality
13. solvation
14. heat of solution
15. unsaturated solution
16. saturated solution
17. supersaturated solution
18. colligative property
19. boiling point elevation
20. freezing point depression

Recommended Reading: (These textbook pages will supplement the information covered in class)

Chapter 16 - (page 516) Solutions

Chapter 19 - (page 664) Acids, Bases, and Salts

Alkaline battery: http://en.wikipedia.org/wiki/Alkaline_battery

Chemistry[edit] In an alkaline battery, the negative electrode is zinc and the positive electrode manganese dioxide. The alkaline electrolyte of potassium hydroxide is not part of the reaction, only the zinc and manganese dioxide are consumed during discharge.

Supersaturated sodium acetate http://ncsu.edu/project/chemistrydemos/Thermochem/SatNaOAc.pdf

https://www.youtube.com/watch?v=HnSg2cl09PI Recrystalization of sodium acetate

https://www.youtube.com/watch?v=0wifFbGDv4I Sodium acetate

Rock candy lab: https://www.learning4kids.net/2015/01/07/make-sugar-crystals-stick/