This homework should be submitted as a hard copy, on actual paper.
Read someone else’s Flying Circus of Physics report. Identify the physical principles behind the phenomenon investigated. Create one quiz question (multiple choice or short answer) that tests understanding of one of the principles.
The reports can be accessed at www.barransclass.com/phys1090/circus/index.html.
Answer one of the following:
Stoichiometry, moles, mole ratios, molar masses, and concentrations are all tools and techniques for figuring what quantities of chemicals to combine for a reaction and how much product you can expect. This should not be an entirely foreign concept: combining specific amounts of different things happens in many other activities, from cooking to construction to seating at a dinner party. Develop an analogy for teaching some aspect of stoichiometry and explain what parallels it has to what you did in this unit.
Every reaction studied in this unit increases entropy. (For that matter, every reaction that ever occurs increases entropy.) The two things a chemical reaction can do to increase entropy is to make its materials become more disordered, or to release heat.
When a chemical system is at equilibrium, the concentrations and amounts of the reactants and products are not changing. However, that does not mean that nothing is happening, or that reactants are no longer changing into products or that products are not reverting back to reactants. Identify and explain what happens in a system at chemical equilibrium.
The rate of a chemical reaction depends on the concentrations of the reactants.
Many of the reactions in this unit involved “physical changes”—converting material from one form to another—rather than “chemical changes”—actual rearrangement of an atom’s chemical bonds. Does this mean that no chemistry was occurring?
Why were these reactions included in this unit? Identify all the reactions in this unit that are “physical” changes, and identify what they each illustrate about chemical equilibrium.
Take your choice of these tasks. Do not submit answers to more than one of them. Just choose one, and submit it. Your answer should thoroughly address all points of the question. An adequate answer will be several paragraphs long.
Submit your homework in hard copy. Please do not submit it electronically! I plan to sit comfortably at home while reading your homework. I do not intend to be trapped in front of my computer.
Warning: Do not turn in paper that has ragged edges! If you write your work in a spiral-bound notebook, trim the edge before submitting it. Papers with ragged edges will be returned unmarked.
Copyright © 2006, Richard Barrans
Revised: 13 November 2009. Maintained by Richard Barrans.
URL: http://www.barransclass.com/phys1090/hw/hwk_12_equil.html