1) Is this a plot of ln[A] vs. t (A = reactant)? The slope of the line from this plot is –k (if the reaction is first order in A), and since k increases with temperature (Arrhenius equation), at higher temperature the slope of the line should be greater.
2) I think that here, all you need to do is use the Arrhenius equation for two temperatures.
ln (k1 / k2) = (Ea / R) (1/T2 �?1/T1)
Plug in the values of k1 and T1 from your experiment, with T2 being 20° more than T1, and solve for k2.
3) I don't know what the reaction is, though I'm thinking maybe hydrolysis of an ester. If so, this might be a control in which a solution with an equal amount of acid catalyst is titrated. This volume of base would be subtracted from the volume used to titrate the sample flask, giving the volume of base that neutralized the hydrolysis product only (a carboxylic acid if you were hydrolyzing an ester).
4) I'm not sure about that one either, I need to see the procedure to tell what's going on. Maybe this titration is done before heating, or before adding the acid catalyst? If no product carboxylic acid (?) has had a chance to form, then the volume of base would be zero (unless the acid catalyst is present, then that would require a small volume of base to neutralize).
Steve
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