Candle+and+Air+Pressure

= Candle and Air Pressure =
 * Grade Level and Topic: **Grades 7,

** Names and Contacts: **

Troy Deveney __ twd122@psu.edu __

Dan Hoy __ dwh5094@psu.edu __

** Educational Standards: **
 * 3.4.7.A Describe concepts about the structure and properties of matter
 * 3.4.7.B Relate energy sources and transfers to heat and temperature

** Instructional Objectives: **

As a result of this lesson students should be able to
 * make predictions based on observations and prior knowledge
 * explain that a combustion reaction makes one CO2 molecule for every two oxygen molecules
 * Explain that a reduction in air molecules decreases the volume of the air

** Content Explanation: **

In order to teach this lesson it is necessary that students be wiling to participate in a discussion. Students must be willing to make predictions and must be able to make observations based on an observable phenomenon. Students should have an understanding of types of matter and chemical reactions for this lesson to be successful. If students have knowledge of the ideal gas law they will be easily able to explain the phenomenon. This lesson will be taught utilizing the predict observe explain method so most of the content will be explained by the instructor after observing the pheonmeon. The reaction of the candle converting oxygen to CO2 will be explained and used to show how a change in the molar quantity of gas particles decreases the volume.

<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">** Administrative Considerations: **

<span style="color: black; font-family: 'Times New Roman',serif; font-size: 12pt;">This lab is an observation and discussion based lab so it will be important to illicit responses from all students to keep them engaged and involved. There are no chemicals or hazardous materials being used in this lab however an open flame must always be approached with caution. This lesson should engage all types of learners because it will force them to study the experimental set-up and use prior and given knowledge to generate explainations. Explanation will be given verbally and students knowledge will be probed with questions if discussion stagnates. Students must be kept on tract through questioning. The observational nature of the lesson should facilitate the understanding by ELL/ESL students.

<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">** Materials, Equipment, and Set Up: **
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">1 large glass jar
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">1 small glass jar
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">candle
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">blue food coloring
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">plate or pan
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">matches
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">beaker for mixing water and dye

<span style="color: black; font-family: 'Times New Roman',serif; font-size: 12pt;">Before the beginning of the lesson the blue dye will be mixed with water in the beaker. Once the students have entered and are ready to view the demonstration the water will be poured onto the plate. The candle will be place in the center of the plate and lit with a match. A jar will be placed over the lit candle and left there until the candle is extinguished.

<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">** Body of Lesson: **

<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">** a) Introduce (2 min) **
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Briefly introduce concepts of pressure and temperature of gases. Show students as water and and blue dye is mixed in beaker.
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Explain to the students how the demonstration will be carried out.

<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">** b) Predict **
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Ask students to make predictions about the outcomes of the demonstration. Make sure that the students make an attempt to explain the reasons for their predictions.
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Encourage students to develop multiple theories and provide reasons for why their prediction might hold true.

<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">** c) Explain **

<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">** d) Observe **
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">First pour the dyed water from the beaker into the pan and place the candle in the middle of the pan. Light the candle and place a jar over it so that the top of the jar is against the bottom of the pan. The candle will burn, which causes the air inside to expand, until a lack of oxygen extinguishes the flame. At this point, the expanded air will contract, creating low pressure inside the jar. The vacuum causes the water in the pan to enter the jar.
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Make sure to follow the procedures that were described to the students.

<span style="font-family: 'Times New Roman',serif; font-size: 12pt;">** e) Explain **
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">After the demonstration is complete ask students to explain what happened. If students have different ideas about the reasons for what occurred, encourage them to develop their explanations and communicate with their peers.
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">If necessary remind students of the concepts explained at the beginning of the lesson.
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">After students discuss their explanations of the demonstration, provide them with the complete explanation and be sure to address any misconceptions.
 * <span style="font-family: 'Times New Roman',serif; font-size: 12pt;">Ask students questions about other potential experiments to test for understanding.