Redox Reactions

Lesson Content

• Lesson Plan Template:

  General Lesson Plan

• Learning Objectives: What should students know and be able to do as a result of this lesson?

  
  
  • Identify a reaction as being redox
  • Calculate oxidation numbers
  • Identify the substance being oxidized and the substance being reduced

   

• Prior Knowledge: What prior knowledge should students have for this lesson?

  
  
  • Metals tend to lose electrons in chemical reactions
  • Nonmetals tend to gain electrons in chemical reactions
  • 5 main types of reactions (single replacement, double replacement, synthesis/combination, decomposition, combustion)

   

• Guiding Questions: What are the guiding questions for this lesson?

  
  

  How are redox reactions related to chemical processes in living things?

   

• Teaching Phase: How will the teacher present the concept or skill to students?

  
  

  Lesson opener/attention getter:

  "Have you ever wondered what powers batteries or what exactly is going on inside a battery? Today we will be learning about oxidation-reduction reactions which are the reason why batteries are able to produce an electrical current."

  Key talking points about the lesson topic:

  Teacher will go through the attached Redox Reactions PowerPoint which covers the following topics:

  1. What a redox reaction is
  2. How to determine whether a reaction is redox or not
  3. How to calculate oxidation numbers
  4. How to determine what the oxidized/reduced species is

   

• Guided Practice: What activities or exercises will the students complete with teacher guidance?

  
  

  Instructions for setting up and leading the activity that the students will complete with teacher guidance:

  1. Students will work on the practice questions (calculating oxidation numbers at end of the PowerPoint) with teacher assistance or in teams based on the knowledge learned in the PowerPoint. The teacher will work with students to guide them to the correct answers (reminding them of the steps for calculating oxidation numbers). Teacher may provide additional examples beyond those found in the PowerPoint.
  2. Teacher could utilize an overhead projector while having the students practice along with the teacher on small white boards or have the students work on paper as the teacher instructs from the classroom whiteboard/chalkboard if more guided practice is deemed necessary.
  3. Once the teacher feels confident that students understand how to calculate oxidation numbers, the students will move onto the Independent Practice Phase where they will find oxidation numbers on their own, compare and identify which species is oxidized and which species is reduced in each redox reaction.

  How will you check for student understanding?

  1. Once the teacher has completed the PowerPoint and questions found therein, the teacher should allow the students to show their understanding by explaining to the teacher the steps to calculating the oxidation numbers. The teacher may choose to utilize any chemical species not used in the worksheet for this purpose.
  2. If they are able to indicate to the teacher how to calculate oxidation numbers to the teacher’s satisfaction, then they are ready enough to attempt the Oxidation/Reduction Practice Worksheet on their own with the teacher circulating.

  Common errors/misconceptions to anticipate and how to respond:

  1. Students often get confused on where the net charge comes from. They also sometimes forget to use the oxidation numbers of the elements they know (Hydrogen and Oxygen) to find the oxidation numbers of the elements they do not know. Carefully remind the students of where these numbers come from and reference the notes will help the students find a consistency in the way they accomplish these problems.
  2. Students also will get oxidation and reduction mixed up in terms of whether the charges go up or down in the chemical reaction. It is important to remind students that the gain of electrons will cause the charge to decrease because electrons are negatively charged. Therefore the loss of electrons will cause an increase in charge. Reminding students of this and the mnemonic "Oil Rig" in the PowerPoint will help them to keep these concepts straight.

   

• Independent Practice: What activities or exercises will students complete to reinforce the concepts and skills developed in the lesson?

  
  

  Instructions for facilitating the activity that the students will complete independently or in groups:

  • Teacher will distribute the worksheet (Oxidation/Reduction Practice) to the students. Students may work with partners to complete the worksheet.

  How will you check for student understanding?

  • The teacher will use the formative assignment key to gauge whether students understand how to find the oxidation numbers and determine which species is oxidized or reduced in a redox reaction.
  • The teacher may also guide the students towards the correct answer through probing questions.

  Common errors/misconceptions to anticipate and how to respond:

  • Students often get confused on where the net charge comes from. They also sometimes forget to use the oxidation numbers of the elements they know (hydrogen and oxygen) to find the oxidation numbers of the elements they do not know. Carefully reminding the students of where these numbers come from and referencing back to the notes will help the students find a consistency in the way they accomplish these problems.
  • Students also will get oxidation and reduction mixed up in terms of whether the charges go up or down in the chemical reaction. It is important to remind students that the gain of electrons will cause the charge to decrease because electrons are negatively charged. Therefore the loss of electrons will cause an increase in charge. Reminding students of this and the pneumonic in the PowerPoint will help them to keep these concepts straight.

   

• Closure: How will the teacher assist students in organizing the knowledge gained in the lesson?

  
  

  Instructions for leading the closing discussion

  The teacher should say something like, "Redox reactions are so important to us. Without the transfer of electrons that happens in these reactions, we would not have electricity to operate any of our electronics. These reactions are also vital to our living systems as they provide energy needed for the basic functions of life. There is an entire subject of Chemistry related to the study of redox reactions. This subject is called Electrochemistry and many of you will learn more about this subject in college."

   

• Summative Assessment

  
  

  How will the students show that they met the learning objectives?

  Students will be provided with several problems in the attached Assessment where they must indicate which species is oxidized or reduced based on their calculations of the oxidation numbers. They will then indicate if the reaction is in fact a redox reaction.

   

• Formative Assessment

  
  

  Specific suggestions for conducting Formative Assessment can be found in the Guided Practice and Independent Practice phases of the lesson where it says, "How will you check for student understanding?"

   

• Feedback to Students

  
  

  Specific suggestions for providing Feedback to Students can be found in the Guided Practice and Independent Practice phases of the lesson where it says, "Common errors/misconceptions to anticipate and how to respond."