Introduction

The "Introduction" of a laboratory report identifies the experiment to be undertaken, the objectives of the experiment, the importance of the experiment, and a general background (specific analysis goes in your discussion section) for understanding the experiment. Your measurable objective should be stated. This is never to familiarize yourself with a technique. This may be one of your personal goals, or the goal of your instructor, but it is not the scientific goal. The background often includes theoretical predictions for what the results should be.

Tips for writing a good introduction:

Move from general to specific: How does your experiment fit into a larger context? I agree that this can be a little difficult with some of the more technique driven labs, but it can be done with some creativity.

Engage the reader: Why should the reader care about what you did?

Review: Review the literature. Normally when you are doing original research, you review the studies that you based your research on. It may be more appropriate to review recent uses of whatever technique or reaction we studying in a lab report situation as it is not exactly original research.

Summarize the key concepts: Your discussion will provide full detail but you need to give your reader enough here so that they can what you were trying to do, even if they don’t understand the details of your discussion. Someone with a knowledge of general chemistry should be able to understand it. If there is a term that a person a level below you would not know, define it.

Learning from published research may be the best way to see all of this working together. Notice below how you are drawn in by a much bigger, more general, problem (stopping the virus that causes polio and herpes) than the one actually being investigated (alkylation of a ketone). Barry Trost is not the only person who can do this. If your lab involves formation of a Schiff base, for example, you could talk about the biological formation and importance of Schiff bases. If you are doing a simple technique, you can look current usage or adaptations of the technique.

Example:

Hamigeran B (1), a metabolite isolated from the poecilosclerid sponge Hamigera taragaenisis … exhibit 100% virus inhibition against both herpes and polio viruses with only slight cytotoxicity throughout the host cells¹. Its structural motif combined with the biological activity stimulates the development of a practical synthesis that can facilitate exploration of the chemical biology of such structural types represented by these scarce natural products. Nicolaou reported the first well known asymmetric sythesis… Our interest stemmed from the question of whether setting the stereochemistry of the quaternary center from which all remaining stereocenters may evolve might be achieved by Pd-catalyzed asymmetric allylic alkylation (AAA)⁵ of a ketone enolate …

Summarized from: Trost, B. M.; Pissot-Soldermann, C.; Chen, I.; Schroeder, G.M. “An Asymmetric Synthesis of Hamigeran B via a Pd Asymmetric Allylic Alkylation for Enantiodiscrimination.” J. Am. Chem. Soc. 2004, 126, 4480.