Thursday, April 19, 2007
Thurs-Day 3
AP: we explained qualitatively via Le Chatelier and quantitatively via Nernst how varying the concentrations in a voltaic cell can either drive the reaction towards the products (increasing E cell) or drive the reaction towards the reactants (decreasing E cell).
We then did several concentration cell problems, one involving a pH meter in which the Ecell is related to the hydronium ion concentration. The other concentrations cells were used to determine the Ksp of sparingly soluble salts.
We then just began to discuss electroLYTIC cells.
Honors: we got into Le Chatelier and kinetic explanations of equilibrium shifts. Be careful with the addition of any solid or liquid substances OR increase in surface area of any solid or liquid substances: solids and liquids generally do not cause a shift in equilibrium; they just increase forward and reverse rates equally.
Regents: we did several Le Chatelier equilibrium problems that covered every possible type of stress on every type of chemical or solution equilibrium. We talked about the "common ion" effect by applying Le Chatelier's principle. We will do one or two more of these problems tomorrow and then we move on to finish the unit.
We then did several concentration cell problems, one involving a pH meter in which the Ecell is related to the hydronium ion concentration. The other concentrations cells were used to determine the Ksp of sparingly soluble salts.
We then just began to discuss electroLYTIC cells.
Honors: we got into Le Chatelier and kinetic explanations of equilibrium shifts. Be careful with the addition of any solid or liquid substances OR increase in surface area of any solid or liquid substances: solids and liquids generally do not cause a shift in equilibrium; they just increase forward and reverse rates equally.
Regents: we did several Le Chatelier equilibrium problems that covered every possible type of stress on every type of chemical or solution equilibrium. We talked about the "common ion" effect by applying Le Chatelier's principle. We will do one or two more of these problems tomorrow and then we move on to finish the unit.
# posted by C @ 3:53 PM 
