Thursday, February 19, 2015

The Lighter Molar Mass Lab

OK.  First things first.  You get some very funny looks when you buy this many lighters at Giant Eagle.  But, if you can push past that, and the occasional derogatory remarks, you have the beginnings of one of the very first inquiry labs I ever tried.

I teach a lesson on the Ideal Gas Law, followed by a lesson on Dalton's Law of Partial pressures.  As part of my Dalton's lesson, I do a demo where I collect the CO2 from a diet coke by water displacement so that kids see why we need to learn about Dalton's Law.  Both lessons are followed by your standard practice problems, including one where we calculate molar mass of a gas.

The next day in the lab I talk briefly about lighters and butane.  I suggest that if we collect a sample of the butane, by taking it out of the lighter, we can make some measurements and calculate its molar mass.  With just that short intro, I send them into the lab to develop a plan.  I won't give them the lighter until they tell me how they will measure all the data they will need.

What I know about kids, having done this lab for many years, is that they don't really know what they need.  And, given the chance, they would just grab the lighter and start collecting gas, only to find out later that they missed a step or a measurement.  They pretty quickly realize that they will apply Dalton's Law and the Ideal Gas Law, use the barometer for the room pressure, a thermometer for the temperature, a flask or something to collect the gas and measure the volume.  The question I ask over and over the day we do this, though, is "how will you measure the mass of the gas?"

Often students say that they will measure the mass of the flask with the water in it and then measure it at the end when it is full with gas.  This idea of massing before and after is pretty standard at this point in the year, but it is tricky when you're dealing with a gas.  Gas goes into the flask and water comes out of the flask, so subtracting the two masses doesn't work.  It's a head scratcher for them.
It's hard to see the lighters in these pictures I am including, but they are there, under the water, beneath the mouth of the flask.  While in this position, students ask great questions:  
  • How much gas should we collect?  
  • Do we need to empty the lighter?  
  • How will we know when its empty?  
  • Do we take the temperature of the air or the water?  
My answers are usually more questions:  
  • How much do you think is a good-sized sample?  
  • Do you need to empty the lighter?  
  • Which temperature is the one that more closely approximates the temperature of the gas you collected?  
  • Isn't it great when you get to make all the decisions about the experiment? 
The results of the experiment come out ok.  Most students calculate the mass to be somewhere between 45 and 80 g/mol; the real value is 58 g/mol.  I like that they have some error because then they also get the opportunity to scrutinize their procedures to consider where they they could make improvements.  The reports are usually easy to write because the students had to do so much thinking BEFORE and DURING the lab.  Sometimes students even race to calculate the molar mass while they are still in class to see if they got close.  Any day where students are anxious to see if their results are good feels like a good day to me. 

I am adding this description to my page of inquiry-based chemistry labs.  If you like this one, check out some of the others.    

Monday, February 16, 2015

A Research Task Template

Last week I attended OETC and presented two sessions.  The first session was about three ways to use technology in high school science classrooms in order to meet the increased demands of Ohio's new learning standards.  I presented the second session with my friend and colleague Tracy Coleman.  We showcased a template we created for teachers to use to make tasks that mirror the types of things students will need to do on the PARCC (math and ELA) and OCBA (science and social studies) tests.

The template is a very simple Google Slides presentation.  The first slide contains the task and links to the other slides on the presentation.  The subsequent slides contain critical components of the task - readings or video or simulations - and are all linked back to the original task slide.  Teachers can drop in a couple of articles and a video to create a research synthesis task.  Here is what the template looks like:

We showed some examples of ways to use the template too.  Tracy created an example where students must read articles and watch a video and write an essay about how we know that Shakespeare authored his works.  She also created an example with opposing viewpoints and asked students to conclude whether or not teachers should be armed.  I created a science example that includes a reading, an atomic structure simulation, and a video about the creation of new elements.  In this example, students answer questions in a Google Form instead of writing an essay. 

We hope that creating the template with an easy and free tool like Google Slides offers few barriers for teachers.  With a little research and a few clicks, teachers can create tasks that they weave into instruction to give students needed practice for these next generation assessments.  Teachers received the template enthusiastically.  Several started creating sample tasks during our session.  What do you think?  Is this something you would use to prepare your students for the upcoming tests?

Sunday, February 15, 2015

3 Easy Steps to Higher Quality

This week I presented a session at OETC on behalf of the Ohio Department of Education as a Network Regional Leader in Science and Technology.  My session was to focus on ways to meet the demands of Ohio's 2010 standards and next generation assessments.  ODE has provided a tool to help teachers evaluate their practice called the Quality Review Rubric.  At first glance, the QRR can be overwhelming, so I copied the language from the rubric into a word cloud generator and came up with the image at the top of this post.  The words that stand out for me are Students (right in the center where they should be), Reading, Writing, Research, Text, Investigations, Scientific, Build, Practices, Appropriate, and Level.  I showcased three tools as ways to incorporate technology while working toward improved instruction in these areas.

Tool #1:  Using ActivelyLearn to meet the Literacy Standards

I wrote about ActivelyLearn earlier this year.  There are so many things to love about this easy to use, free web tool.  Here is the video I played during my session:

Tool #2:  Using Simulations like 123D Circuits to Ready Students for Online Assessments

123D Circuits is a great circuit simulator that is free to use and includes a large toolbox of circuit components.  Many people enjoyed seeing this overview video for a fantastic tool:

Tool #3:   Using Google Forms to Differentiate Instruction

I was surprised that the greatest amount of interest in the session seemed to focus on the way I use Google Forms to differentiate instruction in my classroom.  Here is the video that I created to give a brief overview to how I use this free tool:

Several people asked if I have a template for this.  I don't.  I think it would be hard to use a template because different lessons would have different needs.  I would be happy to share one of my forms with someone, though.

Here are the slides I used during this presentation.  

Though I showcased three tools, I included slides with several other options to improve science literacy, practice using simulations, and differentiate instruction.  The images on the slides are linked to the tools they represent if you want to check some of them out.
I had a great couple of days at OETC and enjoyed meeting many science teachers at this session.  Later this week I will share the slides from my second session too.