Chem 102 Lab
Week #10 (22 March 2007)
Today we shall have two tasks. We will do the math of the last lab to discover what the real formula is for the coordination complex called ferri-thiocyanate. These calculations can be worked on during some of the waiting periods in the synthesis of what we hope are some compounds that smell good - essential essences. There is no quiz today.
As students of science it is very important that you understand the concept of "dynamic equilibrium" versus "static equilibrium". If you stand a coin on edge and it stays put, it is in "static equilibrium" - nothing is moving other than the atomic vibrations due to the coin's having a temperature (warmth is atomic vibration; the more vibration, the hotter the stuff is).
"Dynamic equilibrium." Imagine that you have an unplugged toaster sitting in front of you. It's cold. You peer down in the bread slots and see cold wires. Nothing is happening: no electricity is flowing through the wires, no nuttin' is happening. The toaster is in static equilibrium. But you plug it in, and push down the handle. Hmmm, the filaments transition from cold to brighter and brighter and hotter and hotter. This is NOT equilibrium - there is a net change happening. BUT eventually, the filaments don't get brighter and they don't get hotter - they are as bright and hot as they will get. They will remain in this state for as long as the handle stays down and the electricity flows. This is equilibrium. This is "dynamic" equilibrium because things are happening - the electricity flows and the heat radiates. Another term for dynamic equilibrium is the dynamic steady state.
Your body is in a form that is very nearly in dynamic equilibrium. Cells are multiplying and dying; food goes into you and waste and heat out of you. Yet today you are pretty much like you were yesterday.
Practice Problems dealing with Equilibrium Constants and pH (another type equilibrium).
The Synthesis of an Essential Essence.