There isn't money left in most 2014-2015 science department budgets this late in the school year. For inexpensive chemistry lab ideas, buy my lab book Chemistry on a Budget for $20.56 at amazon.com or $23 at lulu.com. It will take a few weeks to get to you, so order now!
This book contains 13 labs using consumable materials purchased from local stores. There are two versions of each lab, one with a ten-question conclusion and one with directions for a full lab report. This way the teacher has the option! Each lab is two pages to allow for one two-sided handout.
I previously posted several pages about Kinetics and Equilibrium – on 3/30/14 Reaction Rates, 4/2/14 Equilibrium and Le Chatelier’s Principle, and 4/6/14 The Equilbrium Constant and Gibbs Free Energy.
All three posts contain a lot of information – if you haven’t viewed them, you might want to check them out!
I have demonstrated Equilibrium with plastic, interlocking toys on a framed lab table. The frame was made of wood by another teacher, but you could use cardboard from boxes to define the space. To simulate laboratory conditions, the defines the “closed system” .
Students could act to simulate the reaction – perhaps two students link the two reactants together and one or two to pull the parts apart. This simulates the composition and decomposition continually occurring in a reaction. Two to three more students could continually mix the "molecules" to simulate the kinetic energy.
Another student would collect and chart the data – count the number of the reactant pieces and the number of product. The reaction could be run for one minute, then stopped to count the amounts, then run at one minute intervals until equilibrium has been reached.
If you want to simulate a “stress” on the system, add another student to the “composition” team to simulate the addition of a catalyst; or, add more of any component (or remove some) to show the change and establishment of a new equilibrium.
Remember, the concentration does not have units (use brackets around the value) – the “space” framed out is assumed to be a liter.
I wonder if this demo could be developed into a lab, but it might be difficult to get enough material for several lab groups.
*Online there is a page at cloudetal.com that contains several computer demonstrations, http://www.cloudetal.com/tools/chemistry-tools .
Further down on this page is a simulation titled “Reactions and Rates” . Java is required to run this program. Click on the 2nd tab is a way to examine “Many Collisions” where concentrations are controlled at the right of the page, and you can produce a graph of component concentrations.
The 3rd tab titled “Rate Experiments” where initial concentrations can be chosen, the reaction run, and when stopped the amounts of each component are reported and a “strip” chart graphs all of the components. All of the graphs and concentrations are set at zero or "none" until the viewer changes them.
If you have the ability to project this page in your classroom, collect data as a class. Also, this could be an Extra Credit opportunity for your students.
I’d love to hear how you use this simulation – I think it has great possibilities.
Remember, you can check out the Topic List to help you to find past Blog entries.
Have a good weekend!