- Boyle’s Law – the relationship between pressure and volume.
- Charles’s Law – the relationship between volume and temperature.

# Author Archives: fletchtj

# Developing an iOS App – ADE Summer Institute Presentation

This past week I was given the opportunity to present a session on developing apps for the iPhone. I was given 80 minutes to present the process from start to finish. The session drew enough interest to offer it twice which was both a blessing and a curse. I’ve touched up the slides and added a little text to help them stand on their own a little better. Not sure how interesting the slides will be lacking the audio, but feel free to share your comments.

# Titration Simulator

**What is Titration Simulator?**

# Calorimetry Simulator

Quickly set the masses and initial temperatures for your system and go. Observe the output from simulated probes as the system reaches equilibrium. Press “Repeat” to run with the same values or “Setup” to choose a new set.

The Calorimetry Simulator currently has 15 different metals to choose from along with 3 unknowns. Use the simulator to practice calculating the specific heat capacity for the known metals. Once you feel confident with your math, try identifying the three unknowns.

You can also use the simulator to quickly generate your own practice problems to reinforce the concepts. Set up the masses and temperatures, run the trial, record the results. Then, use one or more of the amounts to set up a variety of problems…the best part is you’ll already know the answer!

# Stoichiometry Simulator

**What is StoichSim?**

Beginning chemistry students can use this app to visualize the mathematical relationships occurring between substances in a chemical reaction.

Get a feel for limiting reactants and how they affect product formation. Analyze mass relationships and apply this logic when solving stoichiometry problems.

The user-friendly interface of the “Simulator” allows you to quickly set the desired reactant masses and run multiple trials in a short period of time. Choose from a variety of reactions.

Click over to “My Trials” to view past trials, make comparisons, or plan future trials.

The “Lab Manual” currently has three activities that will help you better understand the role of limiting reactants, mass relationships, and balanced equations.

Use the simulator to quickly generate your own practice problems to reinforce the concepts. Set up the masses, run the trial, record the results. Then, use one or more of the amounts to set up a variety of problems…the best part is you’ll already know the answer!

# Creating a Calorimetry Simulation in Adobe Flash

This past trimester I had my students create simulations using Adobe Flash. This was our second attempt at using Flash to create a simulation. The first attempt occurred during the first trimester (dealing with stoichiometry) and resulted in more of a calculator than a simulator. After collecting some feedback from the students, I set to work at making the second attempt more successful.

I found it difficult to keep everyone on the same page while walking them through the steps required to create our first project. This time around I decided to create a series of movie tutorials that students could use to work at their own pace. This worked unbelievably well, and allowed me to assist students when they hit a bump in the road.

I also provided image copies of the Actionscript code…images because I didn’t want the students to simply copy and paste the code. I wanted the students to experience the manual entry of code and gain an appreciation for the exactness that is required. One thing I found myself saying a lot…”You don’t have to be great at spelling…you just need to be consistent!” Students gained experience in troubleshooting common mistakes…some became good enough to help others spot their mistakes quickly.

Example of Calorimetry Simulation

http://www.chemfiles.com/calorimetry/calorimeter.swf

Project Homepage (with Movies)

http://www.chemfiles.com/calorimetry/index.html

Sidenote: The last step (using the formatDecimals function) is an unnecessary step. A better approach is to use the toFixed(num) method that returns a string with “num” decimal places. Thanks to one of my current students for calling my attention to this new addition in AS3.0.

# Balancing Equations with Mass Relationships

I decided to take a different approach to the stoichiometry unit for my chemistry sections this year. Instead of jumping right into the algorithmic approach of “3-step” problem solving, I decided to have the students complete an Excel Spreadsheet activity. It was my hope that students would see that you could actually obtain the coefficients for a balanced equation through experimental data…and if they saw this, I hoped they would see that you could then use the coefficients to solve experimental problems (the reverse process). In essence, they would see that solving a stoichiometry problem is no more difficult than setting up the correct mass relationship. Then, I could go on to show them the 3-step approach and show them how it accomplishes the same goal.

For the Excel activity, I had the students collect “experimental” data using the following simulation:

http://www.chemfiles.com/flash/mass_relationship1.swf

Students were asked to run at least five different trials and record the data in an Excel spreadsheet. Then, I had the students manipulate the data to arrive at the mass relationship for the amounts of reactants used and amounts of products produced. After determining the simplest mass ratio for the substances, I had the students calculate the simplest mole ratio. The students were then asked to balance the chemical equation in order to see the coefficients and mole ratio numbers match up. From the coefficients, I took them through calculating the simplest mass relationship to show that it was the same as all the other trials. Using the mass relationship, I asked them to answer a stoichiometry question I had asked earlier in the unit…most were able to quickly see the answer.

It seemed rather redundant to take them through so many steps that yielded the same results, but I felt is was important in reinforcing the concepts. I explained that while we wouldn’t always have experimental data to help us find the simplest mass ratio…we could get the same information just as easily from the balanced chemical equation. Thereby, setting up the importance of a “balanced” chemical equation to solving stoichiometry problems.

The results so far have been very promising.

Here’s a link to the movie tutorials I created for the activity:

- Setting up the Spreadsheet
- Calculating Amount of Reactants Used
- Determining the Simplest Mass Ratio
- Determining the Simplest Mole Ratio
- Wrapping it Up!

Here’s an example of a completed Excel file:

Sidenote: If students don’t have access to Microsoft Excel, they might find Google Spreadsheets extremely useful.

# Adobe Flash Projects

Here’s a list of Flash projects that I have created for use by my students in and out of the classroom. The simulations are missing directions mostly because I use the activities in class and explain how they work. If you would like directions for any of the activities or simulations or you have suggestions, let me know.

Reminder: Please do not take any of these without my permission. I am providing the links so that you may use them – not call them your own.

**Activities**

- Polyatomic Ions – Name Game
- Polyatomic Ions – Charge Game
- Polyatomic Ions – Formula Game
- Ionic Compounds – Balance the Charges
- Heat of Reaction (Mg + HCl)
- Orbital Box Diagrams (Elements 1-36 in order)
- Orbital Box Diagrams (Elements 1-36 random)

**Tutorials**

**Lab Simulations**

- Calculate the Specific Heat
- Balancing Equations Through Mass Relationships – Methane + Oxygen
- Balancing Equations Through Mass Relationships – Aluminum + Copper(II) Chloride
- Balancing Equations Through Mass Relationships – Silver Nitrate + Iron(III) Chloride
- Balancing Equations Through Mass Relationships – Sodium Phosphate + Tin(IV) Nitrate
- Molar Volume of Hydrogen/Ideal Gas Law
- Kinetic Energy/PVT Relationship (created by former student)
- Electrolysis (created by same student)

**Miscellaneous**