CHY 252

Organic Chemistry Laboratory I - CHY 252

Chalcone Synthesis

Documents, Instructions, and Useful Websites

Comments for Written Documents in CHY 252/254

There is a detailed document on how to write in the chemical sciences that is posted on this course web page, “instructions for formal reports.” These instructions apply to any written work in the course including your laboratory notes.

First some global issues that I seem to see all the time (these are documented in that web page).

Written Format

The required format for laboratory notes and written reports is complete sentences in Edited Standard Written English (EWSE).

For laboratory notes, the requirements are:

First person,

Past tense,

Active voice.

For written reports, you may use the above format, or:

Third person,

Past tense,

Passive voice.

Do not use both in a document! One or the other!

Particular issues that I often see:

Measurements

· Precision of instruments: Always record measurements to the full precision of the instrument and record what instrument you used.

· When recording a measurement that is less than one, proceed the measurement value with a zero (i.e., not .134 g, record as 0.134 g).

· Place a space between the measurement value and the unit.

· When recording measurements and calculating molar quantities make sure the number of significant figures (s.f.) agree.

Written issues

· Learn how to type superscripts and subscripts. Note that the retention factor in TLC is Rf, where the “f” is a subscript.

· Don’t personify. It’s the reaction mixture, not my reaction mixture. We will try to be as objective as possible.

· Avoid create – we’ll leave that to the deities. We prepare solutions, we synthesize compounds, we record an IR spectrum,…

· Don’t capitalize chemical names unless they are trade names (i.e., 1-phenylethanol is an IUPAC chemical name, Tylenol is a trade name for acetaminophen).

· Spectrum is singular, spectra is plural.

· When describing a drying column, you use an anhydrous salt, so be sure to describe it as anhydrous Na2SO4.

Instrumentation

· You record an IR spectrum or you record a 1H NMR spectrum.

· The units for IR bands are wavenumbers (cm-1).

· The units for NMR resonance chemical shifts are parts per million (ppm).

· When reporting melting point ranges, the range should be no larger than 3 or 4 ˙C from the start of the melt to the sample being completely melted. This requirement will force you to set the voltage low enough so that the rate of temperature increase is low at the melting point range.

· For gas chromatography-mass spectroscopy (GC-MS), you will have one chromatogram (with time on the independent axis) with one or more bands index by their retention time and one or more mass spectra. Each mass spectrum will have m/z (mass/charge) on the independent axis and abundance on the dependent axis. The m/z peaks will be automatically normalized to the largest m/z peak which will be set at 100%. This largest m/z peak is named the base peak.

syllabus - Tracy (pdf )

project overview (pdf)

project reaction scheme (pdf)

schedule (pdf)

MIT techniques videos:

TLC

organic extraction

column chromatography

recrystallization

USM Laboratory Safety Plan

MSDS search site

laboratory check-in list (pdf)