Solution Calorimetry

Calorimetry Lab...report (Chem 312)

The following report will consist of a collection of graphs and handwritten calculations with the following headings:

Introduction

"This report will presents results from a solution calorimetry lab activity involving the following reactions where NaOH is the limiting reagent:"

KOH or NaOH (s) --> NaOH (aq) (1)

KOH or NaOH (s) + HCl (aq) --> NaCl (aq) + H₂O (l) (2)

KOH or NaOH (aq) + HCl (aq)--> NaCl (aq) + H₂O (l) (3)

(YES...you may copy/paste these words/rxn into your lab report...this is all you need to have for your intro unless you wish to add more.)

Methods

Describe the setup and data collection

Results

Experimental data

1) Plot out (with axes labels in Igor) time vs temp data for the three reactions on a single graph.

2) As will be discussed in lab, annotate a single data set (on a different graph using a layout) to show how T_f and T_i were determined, and hence ΔT.

3) Show calculations to (hand written) to determine ΔH₁, ΔH₂, and ΔH₃.

Theoretical Data

1) Use the ∆H_f to calculate theoretical values of ΔH₁, ΔH₂, and ΔH₃.

2) Using the concept of Hess’ Law, use the theoretical values to show that ΔH₁ + ΔH₃ = ΔH₃; include chemical reactions and how they are used to show that ΔH₁ + ΔH₃ = ΔH₂.

Discussion

1) Discuss the relationship between experimental and theoretical values and indicate whether your experimental data “follows” Hess’ Law.

2) Discuss from a molecular-level why the ΔH₁ < 0 (exothermic).

3) Discuss from a molecular-level why the ΔH₃ < 0 (exothermic).

Conclusion

1) Comment of the quality of the experimental data.

2) Suggest sources of error in the experimental setup and potential ways to improve.