The 5 Types of Reactions: Lab in Alignment with the NGSS
HS-PS1-2-"Construct and revise 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."
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This lesson will break down Chemical Reactions into 5 sub-categories: Composition, Decomposition, Single-Replacement, Double-Replacement, and Combustion. To introduce the students to these types of reactions, there will be a brief period of notes. The rest of the class, will be given to the students time to explore these 5 reactions in the lab. One of the types of reactions, Decomposition, will be done as a demo (Elephant's Toothpaste) in an effort to reduce/avoid a mess. Hopefully working in the lab will spark curiosity for the students!
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The 5 Types of Reactions: Lab Lesson Plan
Start of Class:
To start the class, the goals for the day will be written on the board. The goals for this lesson include:
The teacher should go over the tasks for the day as well. The tasks for today's lesson plan include a brief section of notes, a demo to kick off the lab, and then the students will be in the lab for the remainder of the period. The teacher should tell the students that they are expected to remain attentive and on task for the entire hour and that they are expected to finish the lab in one day.
Introduction of Lesson:
The introduction to this lesson will be going over the goal and expectations the teacher has for the day (stated above). A good way to grab students attention for this lesson will be to perform the demonstration (found in the link below). The demo planned for this lesson is known as the Elephant Toothpaste reaction. This is an example of a decomposition reaction.
Elephant Toothpaste Demo Instructions
To start the class, the goals for the day will be written on the board. The goals for this lesson include:
- Students can identify the 5 types of reactions.
a. Composition- A reaction of two substances, typically a metal and a nonmetal, come together to form one compound.
b. Decomposition- A reaction that breaks apart one compound into simpler substances, (usually two elements or an element and a smaller compound).
c. Single-Replacement- A reaction between one compound and one element that produces a different compound and element.
d. Double-Replacement- A reaction between two compounds that are dissolved in water that produces two different compounds, one of which is insoluble.
e. Combustion- A reaction between a Carbon/Hydrogen (and sometimes Oxygen) compound with O2.
The teacher should go over the tasks for the day as well. The tasks for today's lesson plan include a brief section of notes, a demo to kick off the lab, and then the students will be in the lab for the remainder of the period. The teacher should tell the students that they are expected to remain attentive and on task for the entire hour and that they are expected to finish the lab in one day.
Introduction of Lesson:
The introduction to this lesson will be going over the goal and expectations the teacher has for the day (stated above). A good way to grab students attention for this lesson will be to perform the demonstration (found in the link below). The demo planned for this lesson is known as the Elephant Toothpaste reaction. This is an example of a decomposition reaction.
Elephant Toothpaste Demo Instructions
Lesson Instruction:
Prior to the demonstration, the teacher should hand out the "Types of Reactions Lab" worksheet. He/she should then have the students fill in their observations of what happened during the demo in the proper area on the lab worksheet. The teacher will then have the students set their lab worksheet aside and tell them we are going to change gears for just a moment and talk about what happened in the demo and what you can expect to see in the lab that will be done.
This is the point in the lesson that the students should take notes on the 5 types of reactions. The teacher will go over a brief PowerPoint with the information. At the end of the PowerPoint, the teacher will prompt a short discussion relating the demo, notes, and lab with the following questions:
At this point, the teacher should break the students up into 4-8 groups (depending on how many stations can fit in the lab area). Before letting the students go to the lab, instruct the students that they must visit all for stations, Stations A-B, and alert them of the safety hazards. The safety hazards in this lab include the need to wear safety goggles at all times, to wear gloves when handling Silver Nitrate as it can stain your hands, and to not look directly into burning Magnesium.
The students will then follow the instructions spelled out to them on the "Types of Reactions Lab" worksheet. The teacher will be stationed at Reaction C. These procedures are listed below:
Start off at a station and complete the reaction within the five minutes allotted. Make sure to record all observations and to write down reactants. Make sure to clean up your lab station when you are done and to dump chemicals in appropriate waste jars.
Reaction A
1. Add about 1 mL (1 mL » one squirt from the pipette) of calcium chloride solution, CaCl2, to a clean test tube. Next, add about 1 mL of sodium carbonate solution, Na2CO3, to the same test tube. Record your observations. Dispose of solution down the sink.
Reaction B
1. Stand a clean test tube in the test tube rack and add 1-2 mL of Silver Nitrate, AgNO3. Carefully add a piece of copper turnings into test tube.
2. Stir the solution gently and record your observations. Dispose of solution in waste jar.
Reaction C
1. Follow the teacher's instructions to burn methane bubbles in your hands. Make sure your hands are wet and you do not pull hands toward your face when the bubbles ignite.
2. Record observations below.
Reaction D
1. Place a watch glass next to the burner. Examine a piece of magnesium ribbon and record your observations. Using crucible tongs, hold the ribbon in the burner flame until the magnesium starts to burn. DO NOT LOOK DIRECTLY AT THE FLAME. Hold the burning magnesium directly over the watch glass. When the ribbon stops burning, place the remains on the watch glass. Examine this product thoroughly and record your observations. Turn off the burner. Throw waste in jar and wash off watch glass.
After the students have been to each station, they will return to the classroom. The teacher will go over each reaction and ask the students for their ideas of what type of reaction they observed. After this discussion, the students should complete the analysis and conclusion portions of the lab worksheet, and the teacher should collect the lab.
Assessments/Checks for Understanding:
There are two major forms are assessment in this lesson. The first is an informal and continual assessment throughout the lesson with the teacher's prompted conversations. With these dialogues, the teacher can gage how the students are feeling about the instruction (a form of reflective teaching), and how the students are comprehending the material. These conversations can happen during the lab, during and after the PowerPoint notes, and as the students are working on completing the lab hand out.
The second form of assessment for this lesson is more formal. The teacher will collect and grade the lab work the students have done. Based off of the students' responses to the lab question, the teacher can determine if the students reached the goal for the day-- students can identify the 5 types of reactions. The teacher can also use the labs to gage what will need to be covered on the next day of instruction, a day used to reinforce the 5 types of reactions.
Closure/Wrap-Up/Review:
The closure of this lesson will be very brief due to the fact that the lab will take up the majority of the class period. The teacher will collect the lab worksheets and inform the students that they will be graded and handed back tomorrow. The teacher will also give the students a preview of the next lesson, telling them that the next day they will be looking at the 5 types of reactions in more detail. The students will be practicing writing out Chemical Equations for the 5 types of reactions, practice identifying the 5 types of reactions from Chemical Equations, and practice predicting products for the 5 types of chemical equations based off of the reactants given to them.
Prior to the demonstration, the teacher should hand out the "Types of Reactions Lab" worksheet. He/she should then have the students fill in their observations of what happened during the demo in the proper area on the lab worksheet. The teacher will then have the students set their lab worksheet aside and tell them we are going to change gears for just a moment and talk about what happened in the demo and what you can expect to see in the lab that will be done.
This is the point in the lesson that the students should take notes on the 5 types of reactions. The teacher will go over a brief PowerPoint with the information. At the end of the PowerPoint, the teacher will prompt a short discussion relating the demo, notes, and lab with the following questions:
- What did you observe in the demonstration?
- Given that the reaction started with H2O2, can you predict a Chemical Equation?
- What type of reaction was the Elephant Toothpaste demo?
At this point, the teacher should break the students up into 4-8 groups (depending on how many stations can fit in the lab area). Before letting the students go to the lab, instruct the students that they must visit all for stations, Stations A-B, and alert them of the safety hazards. The safety hazards in this lab include the need to wear safety goggles at all times, to wear gloves when handling Silver Nitrate as it can stain your hands, and to not look directly into burning Magnesium.
The students will then follow the instructions spelled out to them on the "Types of Reactions Lab" worksheet. The teacher will be stationed at Reaction C. These procedures are listed below:
Start off at a station and complete the reaction within the five minutes allotted. Make sure to record all observations and to write down reactants. Make sure to clean up your lab station when you are done and to dump chemicals in appropriate waste jars.
Reaction A
1. Add about 1 mL (1 mL » one squirt from the pipette) of calcium chloride solution, CaCl2, to a clean test tube. Next, add about 1 mL of sodium carbonate solution, Na2CO3, to the same test tube. Record your observations. Dispose of solution down the sink.
Reaction B
1. Stand a clean test tube in the test tube rack and add 1-2 mL of Silver Nitrate, AgNO3. Carefully add a piece of copper turnings into test tube.
2. Stir the solution gently and record your observations. Dispose of solution in waste jar.
Reaction C
1. Follow the teacher's instructions to burn methane bubbles in your hands. Make sure your hands are wet and you do not pull hands toward your face when the bubbles ignite.
2. Record observations below.
Reaction D
1. Place a watch glass next to the burner. Examine a piece of magnesium ribbon and record your observations. Using crucible tongs, hold the ribbon in the burner flame until the magnesium starts to burn. DO NOT LOOK DIRECTLY AT THE FLAME. Hold the burning magnesium directly over the watch glass. When the ribbon stops burning, place the remains on the watch glass. Examine this product thoroughly and record your observations. Turn off the burner. Throw waste in jar and wash off watch glass.
After the students have been to each station, they will return to the classroom. The teacher will go over each reaction and ask the students for their ideas of what type of reaction they observed. After this discussion, the students should complete the analysis and conclusion portions of the lab worksheet, and the teacher should collect the lab.
Assessments/Checks for Understanding:
There are two major forms are assessment in this lesson. The first is an informal and continual assessment throughout the lesson with the teacher's prompted conversations. With these dialogues, the teacher can gage how the students are feeling about the instruction (a form of reflective teaching), and how the students are comprehending the material. These conversations can happen during the lab, during and after the PowerPoint notes, and as the students are working on completing the lab hand out.
The second form of assessment for this lesson is more formal. The teacher will collect and grade the lab work the students have done. Based off of the students' responses to the lab question, the teacher can determine if the students reached the goal for the day-- students can identify the 5 types of reactions. The teacher can also use the labs to gage what will need to be covered on the next day of instruction, a day used to reinforce the 5 types of reactions.
Closure/Wrap-Up/Review:
The closure of this lesson will be very brief due to the fact that the lab will take up the majority of the class period. The teacher will collect the lab worksheets and inform the students that they will be graded and handed back tomorrow. The teacher will also give the students a preview of the next lesson, telling them that the next day they will be looking at the 5 types of reactions in more detail. The students will be practicing writing out Chemical Equations for the 5 types of reactions, practice identifying the 5 types of reactions from Chemical Equations, and practice predicting products for the 5 types of chemical equations based off of the reactants given to them.