Lab Report Format

The laboratory notebook is a permanent record of activities carried out in the laboratory. As a permanent record, all entries should be dated and recorded in pen. No pages should be removed from the notebook. Draw a diagonal line through any page that is to be disregarded and provide a brief rationale for disregarding the page. Each experiment that you conduct in this course should be written up, in detail, in your laboratory notebook. Although the style of a notebook will vary by individual, there are certain guidelines that everyone should follow.

Patents have been won and lost on the basis of what was exactly recorded in the notebook.

Table of Contents

The first four pages of the notebook should be reserved for a Table of Contents. Each experiment must be listed according to title, the date on which it was carried out, and the page on which the experiment can be found in the notebook. If your notebook is not already numbered, you should number the pages.

Procedural Outline

Before you enter the lab, you should have recorded in your notebook the experiment title, the date, the purpose of the experiment, a balanced chemical equation for every reaction that you will use, a brief synopsis of the procedures you will follow, and any pre-lab questions. If you will be recording data in a tabular manner and you know the approximate size of the table before you enter lab, you should make a table so that you will not waste valuable lab time.

Data Collection

The data collection portion of the laboratory notebook will be completed while in the laboratory. Data refers to any quantitative or qualitative observations made during the experiment. You should make it a habit to always write descriptions with complete sentences. Neatness is desirable, but you should not be so concerned about neatness that you transcribe data from another piece of paper (or paper towel!) into your notebook. The risk of misplacing – or incorrectly transcribing – crucial data is unacceptable. Do not attempt to erase or obliterate an incorrect entry. Instead, cross it out with a single horizontal line and locate the correct entry as near as possible. Do not write over incorrect numbers. Over time it may become impossible to distinguish the correct entry from the incorrect one. Record in your notebook the names of computer disks and files where programs and data are stored. Printed graphs and program listings should state the file name associated with the printed document. Printed copies of important data collected on a computer should be pasted into your notebook. The lifetime of a printed page is an order of magnitude (or more) greater than the lifetime of a magnetic disk.

The most common mistake students make when collecting their data is not recording enough observations. Be sure that you record all data, both quantitative (measurement data) and qualitative data (observation data). Qualitative data is most often omitted from the lab notebook but it should not be. Qualitative data can be the most useful data when interpreting your results and can help explain why an experiment did not work. Remember to completely label all data with either a data heading on a table or with complete sentence descriptions. Be thorough!!

Lab Reports

Each experiment will contain specific requirements for what should be included, however, all of the reports will contain an introduction and appendices.

Introduction:

The introduction is a short paragraph that contains all the important information that would allow any other student to understand the purpose of the experiment and the important conclusions from the experiment. It might include the important theories, pertinent equations, significant procedures, important glassware or instruments, and an optics diagram. Optics diagrams should be included for every experiment where an optical instrument is used. An example of a very simple introduction is given below:

The concentration of an aqueous solution of sulfuric acid was determined from the density of the solution to be 4.74% H₂SO₄. The density was calculated from Equation 1.

D=m/v Equation 1

The mass was measured with an analytical balance; and the volume was measured with a volumetric pipet. The density is related to the concentration and was converted to % H₂SO₄ by interpolation using Table 1 in the manual.

A couple of stylistic points about scientific writing should be kept in mind when writing your reports. 1) Scientific writing generally uses the passive voice i.e. The concentration of an aqueous solution of sulfuric acid was determined to be 4.74% H₂SO₄. In general, the sentence structure will be: Subject (what will be determined); Verb (passive); and Clause at the end of sentence (how the subject was determined) 2) The third person is always used. (Never use the word "I".)

After the introduction, list all the key results. Give example calculations for each calculation and key steps in any derivation that was needed. Explain whether the results were like expected. If they were not, give possible explanations for the discrepancy. Calculate key statistics on all numerical results. Next, summarize the experiment and answer any post-lab questions. Finally, list any references (including your textbook) that were consulted during the course of the experiment and make a list of all the appendices that are included. The appendices should include the data pages, graphs where requested, data off of strip chart recorders, and any other supporting evidence.

Laboratory is a key component of analytical chemistry courses. You should expect to spend a significant amount of time preparing for lab and analyzing results once you have completed an experiment. The laboratory time has been scheduled so that you should be able to complete all of the experiments in the time allotted if you are prepared when you enter the lab. If you regularly do not finish the experiments in the time allotted, ask your instructor how you can schedule your lab time more effectively.

Part of the score for each lab will be based upon the pre-lab being complete before lab and the completeness of your observations. While in lab you should record all observations and numerical data. I will be collecting your notebooks periodically to assess how good of record you are keeping. After completing the experimental portion of each lab, answer any post lab questions posed and include comments about your results overall.  All lab reports will be due one week after completion of the experiment. Please bring your lab notebook to lecture for sharing of data and discussion.