Unit 3 Part 1: Chemical Reactions, Energy, and Change

Essential Questions:

1. What are the 5 main types of chemical reactions and how are they identified?

2. What are the characteristics of a chemical equation?

3. How is the law of conservation of matter used to determine chemical composition in compounds and reactions?

4. How are chemical equations balanced?

5. What is the role of activation energy and degree of randomness in a chemical reaction?

6. What is a catalyst and what does it do?

7. What are some everyday examples of the use of catalysts in a chemical reaction?

8. What are the indicators of a chemical reactions and how can they be experimentally determined?

9. Describe the energy change that takes place during a physical and a chemical change.

GSE:

SC3. Obtain, evaluate, and communicate information about how the Law of Conservation of Matter is used to determine chemical composition in compounds and chemical reactions.

a. Use mathematics and computational thinking to balance chemical reactions (i.e., synthesis, decomposition, single replacement, double replacement, and combustion) and construct an explanation for the outcome of a simple chemical reaction based on the outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of chemical properties.

b. Plan and carry out an investigation to determine that a new chemical has been formed by identifying indicators of a chemical reaction (e.g., precipitate formation, gas evolution, color change, water production, and changes in energy to the system).

c. Use mathematics and computational thinking to apply concepts of the mole and Avogadro’s number to conceptualize and calculate • percent composition • empirical/molecular formulas • mass, moles, and molecules relationships • molar volumes of gases

d. Use mathematics and computational thinking to identify and solve different types of reaction stoichiometry problems (i.e., mass to moles, mass to mass, moles to moles, and percent yield) using significant figures. (Clarification statement: For elements c and d emphasis is on use of mole ratios to compare quantities of reactants or products and on assessing students’ use of mathematical thinking and not on memorization and rote application of problem-solving techniques.)

e. Plan and carry out an investigation to demonstrate the conceptual principle of limiting reactants.

Vocabulary Unit 3:

1. law of conservation of mass

2. chemical equation

3. synthesis reaction

4. decomposition reaction

5. single replacement reaction

6. double replacement reaction

7. combustion reaction

8. precipitate

9. activity series

10. reactivity

11. collision theory

12. activation energy

13. activated complex

14. catalyst

15. spontaneous process

16. entropy

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

Chapter 11 - (page 344) Chemical Reactions

Chapter 17 - (pages 554 - 583) Thermochemistry

Laws of thermodynamics link: http://physics.about.com/od/thermodynamics/a/lawthermo.htm

Video: Balancing chemical equations. https://www.youtube.com/watch?v=HgB-t4Nq05c

Examples Balancing Equations: http://www.sky-web.net/science/balancing_chemical_equations_examples.htm

http://www.amazingrust.com/Experiments/how_to/Thermite.html Thermite reactions

https://www.youtube.com/watch?v=5q5bzHckSIM (Genie in a bottle demo)

https://www.ck12.org/book/CK-12-Chemistry-Intermediate/section/20.2/ (Gibbs Free Energy calculations and an explanation of reaction spontaneity)

Excellent Thermodynamics page! https://www2.chem.wisc.edu/deptfiles/genchem/netorial/modules/thermodynamics/index.htm

Hess's Law of Heat Summations https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Thermodynamics/Thermodynamic_Cycles/Hesss_Law