UTPA STEM/CBI Courses/Chemical Reactions

Course Title: General Chemistry I

Lecture Topic: Chemical Reactions

Instructor: Dr. Karina Castillo

Institution: South Texas College

Backwards Design

Course Objectives

• Primary Objectives- By the next class period students will be able to:
  • Understand the concepts of oxidation reduction reactions
  • Identify the differences between oxidation and reduction
  • Understand the characteristics of oxidation and reduction reactions

• Sub Objectives- The objectives will require that students be able to:
  • Understand that more than one element can get oxidized and reduced in the same chemical reaction
  • Understand that the electrons gained or lost can be used in different ways.

• Difficulties- Students may have difficulty:
  • Understanding how electrons are lost and gained in oxidation reduction reactions

• Real-World Contexts- There are many ways that students can use this material in the real-world, such as:
  • Fuel cells
  • Cell oxidation

Model of Knowledge

• Concept Map
  • Understanding the difference between oxidation and reduction
  • Identifying oxidizing and reducing agents
  • What elements are more likely to be oxidized and what elements are more likely to be reduced
  • Balancing oxidation-reduction reactions
• Content Priorities
  • Enduring Understanding
    • How to decide if a reaction is oxidation reduction-reaction?
    • Are the electrons lost in a chemical reaction the same as the electrons gained?
    • What are some examples of oxidation-reduction reactions?
  • Important to Do and Know
    • What elements tend to form cations and what elements tend to form anions?
    • To know the relationship between oxidation state, charge and valence electrons
    • To be able to identify between metals and non-metals
  • Worth Being Familiar with
    • Become familiar with oxidation reduction reactions that we encounter every day
    • Standard reduction potentials of various elements
    • Become familiar with oxidation reduction reactions and the production of energy

Assessment of Learning

• Formative Assessment
  • In Class (groups)
    • Assign teams of 3 people and write three questions on the board regarding oxidation reduction reactions and pick them up as they leave.
    • At the end of the class period ask 10 questions and ask them to answer them using the clicker.
  • Homework (individual)
    • Give them a challenging equation where they need to identify the element getting reduced, the element getting oxidized, the oxidizing agent, reducing agent, electrons gained, electrons lost and the practical application of the reaction.
    • Ask students to write one page on oxidation reduction reactions addressing every point discussed in class.
• Summative Assessment
  • Quiz the students in oxidation-reduction reactions
  • Test the students in oxidation-reduction reactions

Legacy Cycle

OBJECTIVE

By the next class period, students will be able to:

• Recognize oxidation reduction reactions.
• Identify oxidizing and reducing agents
• Identify elements that tend to be oxidized and elements that tend to be reduced
• Write half oxidation-reduction reactions
• Balance redox reactions in acidic and basic media

The objectives will require that students be able to:

• Understand the relationship between oxidation state, charge and valence electrons.
• Understand what cations and anions are
• Recognize metals from non-metals

THE CHALLENGE

How do hydrogen-powered automobiles work? What type of chemical reaction is occurring to power this type of cars? What are the chemical components needed for this reaction?

GENERATE IDEAS

• Students will be asked to write what they think the answer to the afforemntioned question is.
• Assign the students into groups and ask them to discuss their answer.
• Students will then come to a conclusion based on that discussion.
• One person per team will report their results to the class.

MULTIPLE PERSPECTIVES

Present a YouTube video showing how a hydrogen fuel cell works.

RESEARCH & REVISE

• Use a power point presentation to lecture on oxidation-reduction reactions.
• Explain the difference between oxidizing and reducing agents.
• Show the different standard reduction potentials for different reactions

TEST YOUR METTLE

At the end of the class period pose 10 questions and ask students to answer them using their clickers.

GO PUBLIC

Quiz Test

Pre-Lesson Quiz

1. What is a fuel cell and does it work?
2. What is rust?
3. What are the main differences between metals and non-metals?
4. What is redox?
5. What is electronegativity?
6. What are antioxidants?
7. Define oxidation
8. Define reduction
9. Define reducing agent
10. Define oxidizing agent
11. What is the oxidation state on an element when is not combined with anything else?
12. What is usually the oxidation state on fluorine?
13. What is the oxidation state of oxygen in peroxides?
14. What is the oxidation state of hydrogen in hydrides?
15. What is the oxidation state of oxygen in compounds other than peroxides?
16. What is the oxidation state of hydrogen in compounds other than hydrides?
17. What is reduction potential?
18. Is hydrogen peroxide an oxidizing or reducing agent?
19. How does bleach remove stains? What type of chemical reaction is occurring?
20. Provide an example of an oxidation-reduction reaction that occurs in biological systems?

Test Your Mettle Quiz

1. Identify the elements getting oxidized and reduced in the following reaction: Mn2+(aq) + NaBiO3(s) → Bi3+(aq) + MnO4− (aq)

2. Identify the oxidizing agent and reducing agent in the following reaction: KMnO4 + Na2SO3 + H2O → MnO2 + Na2SO4 + KOH

3. Balance the following reaction in acidic media: Mn2+(aq) + NaBiO3(s) → Bi3+(aq) + MnO4− (aq)

4. Balance the following reaction in basic media: KMnO4 + Na2SO3 + H2O → MnO2 + Na2SO4 + KOH

5. Provide the oxidation and reduction half reactions for the following: Zn(s) + Cu2+(aq) --> Cu(s) + Zn2+(aq)

6. Balance the two half reactions for the reaction in an acid solution: H2O2 + I- -> I2 + H2O

7. Which two elements are being oxidized in the following reaction? ClO3- + As2S3 --> Cl- + H2AsO4- + SO42-

8.The half-reaction is carried out in an acidic solution: As2S3 + 2 H2AsO4- + 3 SO42- + 28 e- + 36 H+ How many water molecules should be added in order to balance the half-reaction?

9. Explain the relationship between oxidation state, charge and valence electrons.

10. Provide the reaction of the formation of rust. Write out the half oxidation and reduction reaction.