Do you have evidence from the lab that your calorimeter was not a perfect insulator? Assuming that heat was lost from the calorimeter, describe specifically how that would impact the data you recorded and then chase that change through the calculations to show how the error would impact the calculated enthalpy change for a particular reaction. In the past, we have done this lab with roughly 50 mL each of each reactant solution, instead of 25 mL. Yet the Δ T determined experimentally were roughly the same. Explain why that is.

Each student will have slightly different volumes of reactants for each reaction. Yet the results obtained for ΔH1, ΔH2, and ΔH3 should be quite similar and would in fact be quite similar for any range of reactants combined within 25-50 mL, provided that each is accurately measured. Explain why this is the case.

A student misreads the volume of one of the solutions as 25.0 mL when in fact it was 35.0 mL. Step through the quantitative consequences of this error on the heat generated, the Δ T observed, the q calculated, and the Δ H calculated. (Clarification: Both solutions “should” be 25.0 mL or something close, and one of the volumes is accidentally 35.0 mL)

A student pours the reaction solutions into a still wet Styrofoam cup. Step through the quantitative consequences of this error on the heat generated, the Δ T observed, the q calculated, and the Δ H calculated.