Gas Laws : Popcorn

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VIDEO LINKS:

Lab Experiments (Write protocols based on the videos then complete your protocols as you perform experiments in class):

  1. Gas Laws: Popcorn
  2. Imploding the Soda Can

Data analysis and calculations (Use these if you need help with your data and calculations)

Ideal Gas Law

Demonstration (For entertainment):

  1. Pharaoh’s Serpent Demonstration
  2. Ammonia Fountain Demonstration

Experimental Protocol

(Analysis) Write out the protocol for each part of the experiment.  (It can be written in sequential steps.  Complete sentences are not necessary.)  This is the protocol you follow, so be detailed.

Chemical Table

(Representation) Prepare your chemical table including the materials you use in the experiment.  Here is a general template that you may use.
Chemical Name Chemical Formula Molar Mass (g/mol) Hazards Reference PPE
Sodium Chloride NaCl 58.5 Skin irritation https://fscimage.fishersci.com/msds/21105.htm  
           
           
           

Equipment Table

(Analysis) Identify the equipment (type AND size) needed for the experiment and include the name and an image (picture) of each.  Be sure to describe the equipment, how to use it, and why it is suitable for this use.
Equipment Name Equipment Picture Intended Purpose

Data Collection

(Acquiring competencies) Following your detailed protocol, perform all the experiments. Record your observations and take pictures of your key steps in the process. Your observations and images need to be incorporated in your data section and this section should be as detailed as possible as you will use this information to complete your discussion.

Data Processing

  1. (Manipulation) Calculate the percent of the kernels that did not pop (open at all).
  2. (Manipulation) Assuming that minimal water is absorbed by the kernels, show the calculation for finding the volume of the kernels in milliliters and liters.
  3. (Manipulation) Assuming that minimal water is absorbed by the kernels, show the calculation for finding the mass of the kernels in grams.
  4. (Manipulation) Assuming that water vapor is the only gas released by popping popcorn, calculate the total mass of water released by popping.
  5. (Manipulation) Assuming that minimal water is absorbed by the kernels, calculate the percent water in your kernels.
  6. (Manipulation) Calculate the moles of water released in your popping experiment.
  7. (Manipulation) Assuming T to be the boiling point (smoke point) of the oil you are using, find T in Kelvin (around 400oF).
  8. (Manipulation) Using your measured kernel volume, calculated moles of water released and your temperature of boiling oil, calculate the expected pressure inside your kernels.
  9. (Analysis) Identify popping corn as an exo or endo thermic reaction.
  10. (Analysis) Reactions that occur with no external “help” are called spontaneous. Define popping corn as spontaneous or non-spontaneous and explain.
  11. (Assumptions) Fill in the following table using the data and observations from your experiment:
Assumptions made Testing the assumption If assumptions are wrong

Discussion

Write a minimum one-page (12 font, single spaced) discussion on the experiment conducted this week.  The assignment will be graded on completeness, clarity of the explanations and the meaningful integration of the collected and calculated data. Correct grammar and appropriate format for the chemical formulae and chemical reactions is expected. You may use the outline included at the end of this document on how to build your essay to address each category.  
  1. (Existing knowledge, research, and views) Define ideal gases in your own words and describe the conditions under which a gas will behave as an ideal gas.
  2. (Analysis) Describe your experimental conditions and compare them to the conditions described in your answer to Question 1. Explain how this knowledge influences the type of equations that you can use to do your calculations.
  3. (Analysis) Describe and explain the method you used to identify the volume of the kernels. Explain why the volume of the kernels was only found before popping, but after popping was not found. Use your calculated values to support your arguments.
  4. (Analysis) Identify at least one assumption that you made about the volume of water in the kernel. (HINT: there are other things in a kernel).
  5. (Existing knowledge, research, and views) Propose at least one way the volume occupied by water inside of a kernel could be more accurately determined.
  6. (Analysis) Give a supported argument for why this experiment should be done with more than one kernel.
  7. (Existing knowledge, research, and views) Explain why oil is used.
  8. (Analysis) Explain why the inside of the flask was wiped before the mass was recorded.
  9. (Lab skills) Compare the pressure values calculated with others either in your lab or check the internet for results and note your sources. Comment on the accuracy and precision of the experiment.
  10. (Analysis) Predict and explain the result of placing the kernels in an over at low temperature for two hours prior to performing this experiment versus soaking the kernels for 2 hours in water prior to performing the experiment.
  11. (Experimental design) Propose at least one modification that would improve this experiment.
  12. (Existing knowledge, research, and views) Identify the pressure in an unopened can of soda.
  13. (Existing knowledge, research, and views) Find the maximum pressure a soda can is able to resist before exploding.
  14. (Manipulation) Determine if you leave a closed can in a 120°F temperature car, the pressure inside the can and the probability of an explosion.
  15. (Existing knowledge, research, and views) Identify the pressure in an open can of soda before and after boiling the water.
  16. (Analysis) Comment on what happened to the pressure inside the can after it was turned into the water bath.
  17. (Existing knowledge, research, and views) Look up the definition of phreatic eruption and comment on whether its more similar to the explosion of the popcorn or the implosion of the soda can.

Recommended Discussion Outline:

The concepts I used in this experiment were… The most important aspect of this experiment was… The purpose of the experiment was (Hint: it was not to make things explode) … By performing this experiment, I learned…