Equilibrium Pt 1 REACTIONS CAN GO BACKWARDS! Equilibrium – a state of balance where the number of reactants and products don’t change, but there is an equal amount of reactants becoming products as there are products going back to reactants. Forward and reverse reactions at equilibrium are going on at the same time and at the same rate  overall concentrations of each reactant and product to remain constant over time. reactants products

Equilibrium Pt 1 Analogy: A pair of escalators operating between two floors If the same number of people go up as go down in a ten-minute interval, the rate of people moving up equals the rate of people moving down. Overall, any extra people arriving on one floor are canceled out by others leaving the floor. The number of people on each floor will be constant over time, and the population of the two floors is in dynamic equilibrium.

Equilibrium Pt 1 If the number of moles produced in one direction of the reaction is the same as the number consumed in the opposite direction, then the reaction has reached a state of dynamic equilibrium. A typical equation can look like:

Equilibrium Pt 2 The equilibrium concentration of solute in solvent depends on the interactions between the molecules of the two. Equilibrium is reached when competing processes are in balance. -includes tendency for dissolved molecules to spread randomly in the solvent and the competing strength of the bonds and other forces between solutes, solvents, and both

Equilibrium Analogy You’ve now seen two analogies of dynamic equilibrium: clowns juggling balls and people going up and down an escalator. It’s time for you to come up with your own analogy! Here are the requirements: Your analogy can be as crazy as you want it to be. You must draw a picture of your analogy. You must have an explanation of how your analogy demonstrates dynamic equilibrium (3 sentence minimum). -describe what your picture is -explain how it shows a “balance” -explain how it relates to equilibrium 4. I will be checking your progress at the end of class. You should be at least half way done.