exp 17 - answers to some questions

[Zellmer, Robert]

I've received a couple of questions about exp 17.
1) Do NOT use my exp 17 (CrY) example as a one-to-one example for the
    new exp 17 (BAR).  They are very different exps.  About the only thing to
    use my example for is if you're having trouble figuring out how to use Excel
    to do things (not likely since we've used it extensively up to this point) and
    to get an idea of what a zero-order graph should look like and what you
    might get for the 1st and 2nd-order graphs.  I sent those links previously.

    The calculations are different.  In the new BAR exp we are following the
    Abs of the reactant Dye and thus the Abs is directly proportional to the
    conc. of Dye at each time.  In the old exp 17 (CrY) we were getting Abs
    values for the product and then had to calculate the conc. of remaining
    reactant.

    There's an instruction sheet for this new BAR exp in the "handout" for ch 14,

        Chapter 14 - Chemical Kinetics - Handouts<https://www.asc.ohio-state.edu/zellmer.1/chem1250/notes/ch14houts.pdf>
2) You need to include the initial conc of Dye at the moment of mixing
    in the table for each solution.  This is [Dye]o (at time = 0).  It will be
    different for each solution.  It is NOT what was on the bottle (1.05 x 10^-4).
    You can get this by using the dilution eqn.

    For example, lets say we mixed 15.00 mL of the Dye with 15.00 mL of
    H2O and then mixed this with the 10.00 mL of bleach.  We can use
    M2*V2 = M1*V1, where M1 = 1.05 x 10^-4, V1 = 15.00 mL and V2 = 40.00 mL.
    The 40.00 mL is the total volume at the moment of mixing.  This gives
    the conc. of Dye at time zero, the moment of mixing. There's no Abs reading
    for this point.

    Include this data point in your table.  It shouldn't be plotted with the other data
    on your graph since you don't have the absorbance of the dye at the moment
    of mixing before it's had a chance to react with the bleach.  Just put a hyphen
    in the box for Abs for time = 0.

3) There is a post-lab on Carmen. You'll find the module in the "Laboratory"
    module.

Dr. Zellmer
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